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<h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Spline</span></h1>
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<p>Ein <b>Spline <i>n</i>-ten Grades</b> (auch <b>Polynomzug</b>) ist eine Funktion, die stückweise aus <a href="Polynom" title="Polynom">Polynomen</a> höchstens <i>n</i>-ten Grades zusammengesetzt ist. Dabei werden an den Stellen, an denen zwei Polynomstücke zusammenstoßen (man spricht auch von Knoten), bestimmte Bedingungen gestellt, etwa dass der Spline (<i>n-1</i>)-mal <a href="Differenzierbarkeit#Stetige_Differenzierbarkeit_und_höhere_Ableitungen" title="Differenzierbarkeit">stetig differenzierbar</a> ist.
</p><p>Handelt es sich bei dem Spline in all seinen Abschnitten um jeweils eine <i>lineare</i> Funktion, so nennt man den Spline linear (es handelt sich dann um einen <a href="Polygonzug_(Mathematik)" title="Polygonzug (Mathematik)">Polygonzug</a>), analog gibt es <i>quadratische</i>, <i>kubische</i> usw. Splines.
</p><p>Zu den Pionieren der Spline-Erforschung gehören <a href="Isaac_Jacob_Schoenberg" title="Isaac Jacob Schoenberg">Isaac Jacob Schoenberg</a> (ab den 1940er Jahren), <a href="Paul_de_Faget_de_Casteljau" class="mw-redirect" title="Paul de Faget de Casteljau">Paul de Faget de Casteljau</a>, <a href="Pierre_B%C3%A9zier" title="Pierre Bézier">Pierre Bézier</a> und <a href="Carl_de_Boor_(Mathematiker)" title="Carl de Boor (Mathematiker)">Carl de Boor</a>.
</p>
<div class="mw-heading mw-heading2"><h2 id="Allgemeines">Allgemeines</h2></div>
<p>Der Begriff <i>Spline</i> wurde zuerst in einer englischen Veröffentlichung von <a href="Isaac_Jacob_Schoenberg" title="Isaac Jacob Schoenberg">Isaac Jacob Schoenberg</a> im Jahr 1946 für glatte, harmonische, zusammengesetzte mathematische Kurven dritten Grades benutzt.
</p><p>Splines werden vor allem zur <a href="Interpolation_(Mathematik)" title="Interpolation (Mathematik)">Interpolation</a> und <a href="Approximation" title="Approximation">Approximation</a> benutzt. Durch die stückweise Definition sind Splines flexibler als Polynome und dennoch relativ einfach und <a href="Glatte_Kurve" title="Glatte Kurve">glatt</a>. Dadurch ergeben sich bei der <a href="Spline-Interpolation" title="Spline-Interpolation">Spline-Interpolation</a> nicht die Nachteile, die durch die starke Oszillation von Polynomen höheren Grades und deren Unbeschränktheit bei der <a href="Polynominterpolation" title="Polynominterpolation">Polynominterpolation</a> entstehen (<a href="Polynominterpolation#Runges_Phänomen" title="Polynominterpolation">Runges Phänomen</a>). Splines lassen sich auch gut benutzen, um <a href="Kurve_(Mathematik)" title="Kurve (Mathematik)">Kurven</a> darzustellen. Hier finden sie Einsatz im <a href="Computer-aided_design" class="mw-redirect" title="Computer-aided design">CAD</a>. Mathematisch analog lassen sich auf beide Weisen nicht nur Kurven, sondern auch Flächen beschreiben.
</p><p><i>Wortherkunft:</i> Der Begriff stammt aus dem <a href="Schiffbau" title="Schiffbau">Schiffbau</a>: eine lange, dünne Latte (<a href="Straklatte" title="Straklatte">Straklatte</a>, englisch <i>spline</i>), die an einzelnen Punkten durch <a href="Molch_(Schiffbau)" title="Molch (Schiffbau)">Molche</a> fixiert wird, biegt sich genau wie ein kubischer Spline mit natürlicher <a href="Randbedingung" title="Randbedingung">Randbedingung</a>. Dabei wird die Spannungsenergie minimal.
</p>
<div class="mw-heading mw-heading2"><h2 id="Spline-Raum">Spline-Raum</h2></div>
<p>Funktionen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p\colon {[\tau _{0},\tau _{n-1}[}\rightarrow \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>:<!-- : --></mo>
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<mo stretchy="false">[</mo>
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<mo stretchy="false">→<!-- → --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
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<annotation encoding="application/x-tex">{\displaystyle p\colon {[\tau _{0},\tau _{n-1}[}\rightarrow \mathbb {R} }</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/327e1d4ef18caacc5b234311f55b8cb45a1db0ba.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-left: -0.089ex; width:16.318ex; height:2.843ex;" alt="{\displaystyle p\colon {[\tau _{0},\tau _{n-1}[}\rightarrow \mathbb {R} }" loading="lazy"></span>, die sich in jedem der Teilintervalle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{i},\tau _{i+1}[}">
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
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<mo>,</mo>
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<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
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</msub>
<mo stretchy="false">[</mo>
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</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{i},\tau _{i+1}[}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ce1f413df8d1630e0207313e86580259da037660.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:8.06ex; height:2.843ex;" alt="{\displaystyle [\tau _{i},\tau _{i+1}[}" loading="lazy"></span> einer streng wachsenden Knotenfolge <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau :=(\tau _{i})_{i=0,.\ldots ,n-1}\in \mathbb {R} ^{n}}">
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<mrow class="MJX-TeXAtom-ORD">
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<annotation encoding="application/x-tex">{\displaystyle \tau :=(\tau _{i})_{i=0,.\ldots ,n-1}\in \mathbb {R} ^{n}}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/cd948a8b753e7f73d86e46fdd49ba712e8350da9.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:23.594ex; height:3.009ex;" alt="{\displaystyle \tau :=(\tau _{i})_{i=0,.\ldots ,n-1}\in \mathbb {R} ^{n}}" loading="lazy"></span> als Polynome mit Maximalgrad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d\in \mathbb {Z} _{\geq 0}}">
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<annotation encoding="application/x-tex">{\displaystyle d\in \mathbb {Z} _{\geq 0}}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/07d1fecf772a9909ef5c4440e5844b6f29894bba.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.94ex; height:2.676ex;" alt="{\displaystyle d\in \mathbb {Z} _{\geq 0}}" loading="lazy"></span> darstellen lassen, heißen <i>stückweise Polynomfunktionen</i> auf <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
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<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> (mit Maximalgrad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d}">
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<mrow class="MJX-TeXAtom-ORD">
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<annotation encoding="application/x-tex">{\displaystyle d}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e85ff03cbe0c7341af6b982e47e9f90d235c66ab.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.216ex; height:2.176ex;" alt="{\displaystyle d}" loading="lazy"></span>). Außer diesem einfachen Aufbau aus Polynomabschnitten verlangt man bei Splines auch noch maximale Glattheit.
</p><p>Der <i>Spline-Raum</i> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle S_{d,\tau }}">
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<annotation encoding="application/x-tex">{\displaystyle S_{d,\tau }}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ac811066bc60a4f26effdcd62a6251aadd36a680.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:3.824ex; height:2.843ex;" alt="{\displaystyle S_{d,\tau }}" loading="lazy"></span> ist der <a href="Vektorraum" title="Vektorraum">Vektorraum</a> aller <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (d-1)}">
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
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<annotation encoding="application/x-tex">{\displaystyle (d-1)}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d220ad260fcc368cb5c1e92a8253f33695f20940.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.028ex; height:2.843ex;" alt="{\displaystyle (d-1)}" loading="lazy"></span>-mal stetig differenzierbaren stückweisen Polynomfunktionen auf <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
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<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> mit Maximalgrad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d}">
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<mrow class="MJX-TeXAtom-ORD">
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<annotation encoding="application/x-tex">{\displaystyle d}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e85ff03cbe0c7341af6b982e47e9f90d235c66ab.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.216ex; height:2.176ex;" alt="{\displaystyle d}" loading="lazy"></span>.
</p><p>Bei der Konstruktion von Splines erweisen sich die <i>abgeschnittenen Potenzfunktionen</i>
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (u)_{+}^{d}:={\begin{cases}0&{\text{ für}}\quad u<0\\u^{d}&{\text{ für}}\quad u\geq 0\end{cases}}}">
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<p>mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d=0,1,\ldots }">
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<annotation encoding="application/x-tex">{\displaystyle d=0,1,\ldots }</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d901cc8ca47819e2a10b3d1c4fc9df05d4b438e3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:11.43ex; height:2.509ex;" alt="{\displaystyle d=0,1,\ldots }" loading="lazy"></span> als nützlich. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (u)_{+}^{d}}">
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<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (u)_{+}^{d}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1f94bf6e43a2aa774e826e68fb37990669f43239.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:4.65ex; height:3.176ex;" alt="{\displaystyle (u)_{+}^{d}}" loading="lazy"></span> ist für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>d</mi>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle d=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c87f7389ad2498c0f93551ec4fc92a882548484f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.477ex; height:2.176ex;" alt="{\displaystyle d=0}" loading="lazy"></span> die <a href="Heaviside-Funktion" title="Heaviside-Funktion">Sprungfunktion</a>, für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d=1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>d</mi>
<mo>=</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle d=1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/958b426c5ace91d4fb7f5a3becd7b21dba288d50.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:5.477ex; height:2.176ex;" alt="{\displaystyle d=1}" loading="lazy"></span> die Rampenfunktion, und für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d\geq 1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>d</mi>
<mo>≥<!-- ≥ --></mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle d\geq 1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/33476a779aa3e8bc64413c16f777ef15e9d78df6.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:5.477ex; height:2.343ex;" alt="{\displaystyle d\geq 1}" loading="lazy"></span> ist diese Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (d-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (d-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d220ad260fcc368cb5c1e92a8253f33695f20940.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.028ex; height:2.843ex;" alt="{\displaystyle (d-1)}" loading="lazy"></span>-mal stetig differenzierbar.
</p><p>Jede stückweise Polynomfunktion auf <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> mit Maximalgrad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>d</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle d}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e85ff03cbe0c7341af6b982e47e9f90d235c66ab.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.216ex; height:2.176ex;" alt="{\displaystyle d}" loading="lazy"></span> ist mit eindeutig bestimmten Koeffizienten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c_{i,j}\in \mathbb {R} }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>∈<!-- ∈ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi mathvariant="double-struck">R</mi>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c_{i,j}\in \mathbb {R} }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d770daf8a78b56998e5e51d866a23c3237092a77.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:7.46ex; height:2.843ex;" alt="{\displaystyle c_{i,j}\in \mathbb {R} }" loading="lazy"></span>, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (i=0,\ldots ,d;\ j=0,\ldots ,n-2)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
<mo>;</mo>
<mtext> </mtext>
<mi>j</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (i=0,\ldots ,d;\ j=0,\ldots ,n-2)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/bcd2acad97993f047b09e8d0b3ab720e84efeaca.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:30.676ex; height:2.843ex;" alt="{\displaystyle (i=0,\ldots ,d;\ j=0,\ldots ,n-2)}" loading="lazy"></span> in der Form
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p(u)=\sum _{j=0}^{n-2}\sum _{i=0}^{d}c_{i,j}(u-\tau _{j})_{+}^{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</munderover>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</munderover>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p(u)=\sum _{j=0}^{n-2}\sum _{i=0}^{d}c_{i,j}(u-\tau _{j})_{+}^{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38b43b5ee8446443d1642e3b4b3143b06bb8fcd3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.338ex; margin-left: -0.089ex; width:27.338ex; height:7.676ex;" alt="{\displaystyle p(u)=\sum _{j=0}^{n-2}\sum _{i=0}^{d}c_{i,j}(u-\tau _{j})_{+}^{i}}" loading="lazy"></span></dd></dl>
<p>darstellbar. Da Splines <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (d-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (d-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d220ad260fcc368cb5c1e92a8253f33695f20940.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.028ex; height:2.843ex;" alt="{\displaystyle (d-1)}" loading="lazy"></span>-mal stetig differenzierbar sein sollen, müssen bei ihnen die Koeffizienten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c_{i,j}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c_{i,j}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8504228ae66c6c24cc403c35a3df8d78771c9492.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:2.941ex; height:2.343ex;" alt="{\displaystyle c_{i,j}}" loading="lazy"></span> für die niedrigeren Potenzen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,d-1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,d-1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/98e1dc0278b344c43d8f814e36d212836fb20026.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:15.46ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,d-1}" loading="lazy"></span>, die die Differenzierbarkeitsforderung nicht erfüllen, an den inneren Knoten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle j=1,\ldots ,n-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>j</mi>
<mo>=</mo>
<mn>1</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle j=1,\ldots ,n-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7efe3da7eb0d6b27b78885afe33047f59cae2af7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.027ex; width:15.821ex; height:2.509ex;" alt="{\displaystyle j=1,\ldots ,n-2}" loading="lazy"></span> verschwinden.
Splines <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p\in S_{d,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>∈<!-- ∈ --></mo>
<msub>
<mi>S</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p\in S_{d,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8f9703bce2c74d6bbf5b75fbf5fd7cbf399fbb3d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; margin-left: -0.089ex; width:7.924ex; height:2.843ex;" alt="{\displaystyle p\in S_{d,\tau }}" loading="lazy"></span> haben also die Darstellung
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p(u)=\sum _{i=0}^{d}c_{i,0}(u-\tau _{0})_{+}^{i}+\sum _{j=1}^{n-2}c_{d,j}(u-\tau _{j})_{+}^{d}.}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</munderover>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mn>0</mn>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msubsup>
<mo>+</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
<mo>=</mo>
<mn>1</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</munderover>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msubsup>
<mo>.</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p(u)=\sum _{i=0}^{d}c_{i,0}(u-\tau _{0})_{+}^{i}+\sum _{j=1}^{n-2}c_{d,j}(u-\tau _{j})_{+}^{d}.}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8dbaa5fef3ea94e8367e64924f75428e6798f800.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.338ex; margin-left: -0.089ex; width:43.764ex; height:7.676ex;" alt="{\displaystyle p(u)=\sum _{i=0}^{d}c_{i,0}(u-\tau _{0})_{+}^{i}+\sum _{j=1}^{n-2}c_{d,j}(u-\tau _{j})_{+}^{d}.}" loading="lazy"></span></dd></dl>
<p>Die (auf <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{0},\tau _{n-1}]}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">]</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{0},\tau _{n-1}]}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0bb8c42e175c8b7f5486ac66fe6d1d933b5bb1aa.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:8.733ex; height:2.843ex;" alt="{\displaystyle [\tau _{0},\tau _{n-1}]}" loading="lazy"></span> eingeschränkten) Funktionen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (u-\tau _{0})_{+}^{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (u-\tau _{0})_{+}^{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/01880e3097cd29d5a2c16db64476a5b079a30cc6.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:9.561ex; height:3.176ex;" alt="{\displaystyle (u-\tau _{0})_{+}^{i}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,d}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,d}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9a73e999a6bbcee960fa9cf970fb536c1133c56b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:11.457ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,d}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (u-\tau _{j})_{+}^{d}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (u-\tau _{j})_{+}^{d}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5aa6403798e1dce9d84e2ecc10055f61467cd1e2.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:9.416ex; height:3.176ex;" alt="{\displaystyle (u-\tau _{j})_{+}^{d}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle j=1,\ldots ,n-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>j</mi>
<mo>=</mo>
<mn>1</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle j=1,\ldots ,n-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7efe3da7eb0d6b27b78885afe33047f59cae2af7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.027ex; width:15.821ex; height:2.509ex;" alt="{\displaystyle j=1,\ldots ,n-2}" loading="lazy"></span> stellen also zusammen eine Basis für den Splineraum <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle S_{d,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>S</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle S_{d,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ac811066bc60a4f26effdcd62a6251aadd36a680.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:3.824ex; height:2.843ex;" alt="{\displaystyle S_{d,\tau }}" loading="lazy"></span> dar.
Damit ist der Splineraum <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (n+d-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo>+</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (n+d-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/dc03d760a0c017ff5f45b2fe595710f17a528c0f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.263ex; height:2.843ex;" alt="{\displaystyle (n+d-1)}" loading="lazy"></span>-dimensional.
</p><p>Die <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (d-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (d-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d220ad260fcc368cb5c1e92a8253f33695f20940.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.028ex; height:2.843ex;" alt="{\displaystyle (d-1)}" loading="lazy"></span>-malige Differenzierbarkeit der Splines kann man gezielt an vorgegebenen Knotenpunkten wieder abschwächen. In obiger Darstellung erreicht man das durch Wiederhinzunehmen ausgewählter Basisfunktionen niedrigeren Grades an inneren Knoten. Beim <a href="Algorithmus" title="Algorithmus">Algorithmus</a> von De-Boor zur Darstellung von Splines ergibt sich das automatisch, wenn man mehrfache Knoten in der Knotensequenz zulässt, genauer die Forderung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}<\tau _{i+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo><</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}<\tau _{i+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9911aa38fe04efe466975dac76d0e4821a974b04.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:8.831ex; height:2.176ex;" alt="{\displaystyle \tau _{i}<\tau _{i+1}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,n-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,n-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9d9325c3e4c764c7b4ab2f764a0a0ceae541ae1e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:15.639ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,n-2}" loading="lazy"></span> abschwächt zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}\leq \tau _{i+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>≤<!-- ≤ --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}\leq \tau _{i+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6f22bbea69fb586d087c695ab3f66ee31cd9a3f5.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:8.831ex; height:2.343ex;" alt="{\displaystyle \tau _{i}\leq \tau _{i+1}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,n-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,n-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9d9325c3e4c764c7b4ab2f764a0a0ceae541ae1e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:15.639ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,n-2}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}<\tau _{i+d+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo><</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>d</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}<\tau _{i+d+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/90fa1a48df41b5e99539ac0833654f4a74dfda6a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:10.969ex; height:2.176ex;" alt="{\displaystyle \tau _{i}<\tau _{i+d+1}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,n-d-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,n-d-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/56065a8c71a59ba876c89054bd045ad89881b637.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:19.695ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,n-d-2}" loading="lazy"></span>.
</p><p>Die in Mathematik und Technik genutzten Varianten der Splines, wie B-Splines oder kubische Splines, unterscheiden sich im Wesentlichen durch die für den Spline-Raum eingesetzte Basis.
</p>
<div class="mw-heading mw-heading3"><h3 id="Grad_und_Ordnung">Grad und Ordnung</h3></div>
<p>Spline-Kurven werden in der Regel entweder, wie oben beschrieben, über den Grad der stückweise zusammengesetzten Polynome definiert oder über deren Ordnung. Hierbei werden für den Grad meist die Buchstaben <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>d</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle d}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e85ff03cbe0c7341af6b982e47e9f90d235c66ab.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.216ex; height:2.176ex;" alt="{\displaystyle d}" loading="lazy"></span> oder <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span> verwendet, während es üblich ist, für die Ordnung den Buchstaben <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle k}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>k</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle k}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3c9a2c7b599b37105512c5d570edc034056dd40.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.211ex; height:2.176ex;" alt="{\displaystyle k}" loading="lazy"></span> zu verwenden. Hierbei gilt der Zusammenhang:
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle k=d+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>k</mi>
<mo>=</mo>
<mi>d</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle k=d+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5472bf3e4317d4053645228c52317420f9f99e6e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:9.528ex; height:2.343ex;" alt="{\displaystyle k=d+1}" loading="lazy"></span></dd></dl>
<div class="mw-heading mw-heading2"><h2 id="Kubische_Splines">Kubische Splines</h2></div>
<div class="sieheauch" role="navigation" style="font-style:italic;"><span class="sieheauch-text">Siehe auch</span>: <a href="Spline-Interpolation#Der_kubische_C²-Spline" title="Spline-Interpolation">Kubischer C<sup>2</sup>-Spline</a> und <a href="Bikubische_Filterung" class="mw-redirect" title="Bikubische Filterung">Bikubische Filterung</a></div>
<p>Kubische Splines werden unter anderem zur Berechnung des Bahnverlaufs bei <a href="Achterbahn" title="Achterbahn">Achterbahnen</a> verwendet, um ruckartige Beschleunigungswechsel für die Fahrgäste zu vermeiden. Kubische Splines finden weitere Anwendung bei der exakten Verlegung der Schienen bei Hochgeschwindigkeitsstrecken der <a href="Eisenbahn" title="Eisenbahn">Eisenbahn</a>. Auch beim Entwurf von Kurven und Oberflächen (sogenannte „Freiformkurven und -flächen“), wie sie häufig im Schiff-, Flugzeug- und Automobilbau vorkommen, sind Splines von Bedeutung.
</p><p>Splines eignen sich für solche Anwendungen, weil für jeden Polynomabschnitt Randbedingungen sowohl in Form von Punkten als auch in Form von Werten für die erste und zweite <a href="Differentialrechnung" title="Differentialrechnung">Ableitung</a> (und abhängig davon Steigung und Krümmung bzw. Kurvenradius) vorgegeben werden können. Dadurch kann eine über den gesamten Kurvenverlauf stetige Krümmung erreicht werden. So werden Querbeschleunigungen beim Abfahren der Kurve immer allmählich aufgebaut bzw. an den Knotenpunkten vorgegebene Werte eingehalten.
</p><p><a href="Burmester-Schablone" title="Burmester-Schablone">Burmester-Schablonen</a> stellen kubische Splines dar. Diese Schablonen werden genutzt, um <a href="Ausgleichskurve" class="mw-redirect" title="Ausgleichskurve">Ausgleichskurven</a> von Wertescharen zu zeichnen.
</p>
<div class="mw-heading mw-heading2"><h2 id="B-Splines">B-Splines</h2></div>
<p><i>B-Spline</i> ist die Kurzform von <i>Basis-Spline</i>. Im Kontext <a href="Numerische_Mathematik" title="Numerische Mathematik">numerischer</a> Verfahren, wo Splines häufig eingesetzt werden, entscheidet die Wahl der Basis für den Spline-Raum über eventuelle <a href="Rundungsfehler" title="Rundungsfehler">Rundungsfehler</a> und damit über die praktische Einsetzbarkeit. Eine bestimmte Basis hat sich hier als am besten geeignet herausgestellt: Sie ist numerisch stabil und erlaubt die Berechnung von Werten der Spline-Funktion mittels einer Drei-Term-<a href="Rekursion" title="Rekursion">Rekursion</a>. Diese sogenannten B-Spline-Basisfunktionen haben einen <a href="Kompakter_Raum" title="Kompakter Raum">kompakten</a> <a href="Tr%C3%A4ger_(Mathematik)" title="Träger (Mathematik)">Träger</a>, sie sind nur auf einem kleinen <a href="Intervall_(Mathematik)" title="Intervall (Mathematik)">Intervall</a> von Null verschieden. Änderungen der Koeffizienten wirken sich also nur lokal aus.
</p><p>Carl de Boor weist in seinem Artikel<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> <i>B(asic) Spline Basics</i> darauf hin, dass der Begriff B-Spline ursprünglich für bestimmte Splines mit minimalem Träger eingeführt wurde, dass sich jedoch im Bereich von <a href="Computer_Aided_Geometric_Design" class="mw-redirect" title="Computer Aided Geometric Design">Computer Aided Geometric Design</a> die etwas unglückliche Verwendung des Begriffs B-Spline für Splines eingebürgert hat, die in der B-Spline-Basis dargestellt werden.
</p>
<div class="sieheauch" role="navigation" style="font-style:italic;"><span class="sieheauch-text">Siehe auch</span>: <a href="Faltung_(Mathematik)" title="Faltung (Mathematik)">Faltung (Mathematik)</a></div>
<div class="mw-heading mw-heading3"><h3 id="Definition">Definition</h3></div>
<p>Die als <i>Basis-Splines</i> (B-Splines) bezeichneten <a href="Basisfunktion" class="mw-redirect" title="Basisfunktion">Basisfunktionen</a> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }\ (i=0,\ldots ,n-p-2)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mtext> </mtext>
<mo stretchy="false">(</mo>
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }\ (i=0,\ldots ,n-p-2)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e7ae3c265f018cb1deb25ce98190d64b563973e0.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:27.296ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }\ (i=0,\ldots ,n-p-2)}" loading="lazy"></span> des Grads <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span> mit Knotenvektor
<span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\quad (n\geq 2\,p)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
<mo>=</mo>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mspace width="1em"></mspace>
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo>≥<!-- ≥ --></mo>
<mn>2</mn>
<mspace width="thinmathspace"></mspace>
<mi>p</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\quad (n\geq 2\,p)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81a1282d02be5c55d66a10401aa529a38716ec12.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:29.037ex; height:2.843ex;" alt="{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\quad (n\geq 2\,p)}" loading="lazy"></span>
sind von Curry und Schoenberg 1947 bis auf die Normierung in folgender Form eingeführt worden:<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)=(\tau _{i+p+1}-\tau _{i})[\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
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</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<msub>
<mo stretchy="false">]</mo>
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo accent="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)=(\tau _{i+p+1}-\tau _{i})[\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/fbefc97ce5fec708b86347691b8e5d4e351f444d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:48.377ex; height:3.176ex;" alt="{\displaystyle N_{i,p,\tau }(u)=(\tau _{i+p+1}-\tau _{i})[\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}" loading="lazy"></span></dd></dl>
<p>Dabei steht <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<msub>
<mo stretchy="false">]</mo>
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo accent="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/88d0fd61ab90d20bcf8c7c4799a2e154c8872dc8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:24.395ex; height:3.176ex;" alt="{\displaystyle [\tau _{i},\ldots ,\tau _{i+p+1}]_{\overline {u}}({\bar {u}}-u)_{+}^{p}}" loading="lazy"></span> für die <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (p+1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (p+1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7da0746babaf86fc30da6b03fa83177f699790ce.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.982ex; height:2.843ex;" alt="{\displaystyle (p+1)}" loading="lazy"></span>-ste <a href="Dividierte_Differenzen" class="mw-redirect" title="Dividierte Differenzen">dividierte Differenz</a> der abgeschnittenen Potenzfunktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (\tau -u)_{+}^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>τ<!-- τ --></mi>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (\tau -u)_{+}^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f1eccaef08ac82a97ad07498e0c57ad33eaf68b0.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.692ex; height:3.176ex;" alt="{\displaystyle (\tau -u)_{+}^{p}}" loading="lazy"></span> bzgl. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span>.
Die dividierte Differenz <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [x_{0},\ldots ,x_{d}]_{x}f(x)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msub>
<msub>
<mo stretchy="false">]</mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>x</mi>
</mrow>
</msub>
<mi>f</mi>
<mo stretchy="false">(</mo>
<mi>x</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [x_{0},\ldots ,x_{d}]_{x}f(x)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/84760e1aee384cc93137ae193f5d6539c0b90d82.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:16.868ex; height:2.843ex;" alt="{\displaystyle [x_{0},\ldots ,x_{d}]_{x}f(x)}" loading="lazy"></span> ist der zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x^{d}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x^{d}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e1def89db6c549faae1ec80a25c654c900cf3386.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.422ex; height:2.676ex;" alt="{\displaystyle x^{d}}" loading="lazy"></span> gehörige Koeffizient im (eindeutig gegebenen) Polynom <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c_{0}+c_{1}x+c_{2}x^{2}+\ldots +c_{d}x^{d}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>+</mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mi>x</mi>
<mo>+</mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msup>
<mo>+</mo>
<mo>…<!-- … --></mo>
<mo>+</mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msub>
<msup>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c_{0}+c_{1}x+c_{2}x^{2}+\ldots +c_{d}x^{d}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0537c65fa0fe609b0d109917dca22ff71d0b30e3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:28.502ex; height:3.009ex;" alt="{\displaystyle c_{0}+c_{1}x+c_{2}x^{2}+\ldots +c_{d}x^{d}}" loading="lazy"></span>, das die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an den Stellen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{0},\ldots ,x_{d}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{0},\ldots ,x_{d}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6f8ad45506bc015ed67b4e4fbed50deb05f2e0d1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:9.984ex; height:2.009ex;" alt="{\displaystyle x_{0},\ldots ,x_{d}}" loading="lazy"></span> interpoliert. Stimmen die Werte von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle k}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>k</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle k}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3c9a2c7b599b37105512c5d570edc034056dd40.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.211ex; height:2.176ex;" alt="{\displaystyle k}" loading="lazy"></span> der Variablen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x_{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>x</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x_{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e87000dd6142b81d041896a30fe58f0c3acb2158.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.129ex; height:2.009ex;" alt="{\displaystyle x_{i}}" loading="lazy"></span> überein, so interpoliert das Polynom die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>f</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle f}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/132e57acb643253e7810ee9702d9581f159a1c61.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.279ex; height:2.509ex;" alt="{\displaystyle f}" loading="lazy"></span> an dieser Stelle bis zur <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (k-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>k</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (k-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e69f74fa2adbbab50f6969acb2af719045435461.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:7.023ex; height:2.843ex;" alt="{\displaystyle (k-1)}" loading="lazy"></span>-ten Ableitung (oskulierende Interpolation, engl. ‘osculating interpolation’).
</p><p>In obiger Definition von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/60f3ac8e2b346a7087627be0542c3d305d0ea236.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.396ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)}" loading="lazy"></span> gilt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ({\bar {u}}-u)_{+}^{p}=({\bar {u}}-u)^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
<mo>=</mo>
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ({\bar {u}}-u)_{+}^{p}=({\bar {u}}-u)^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/189e1292a22653ada95d268af9f20cac7a12c073.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:20.287ex; height:3.176ex;" alt="{\displaystyle ({\bar {u}}-u)_{+}^{p}=({\bar {u}}-u)^{p}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\bar {u}}=\tau _{i},\ldots ,\tau _{i+p+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>=</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\bar {u}}=\tau _{i},\ldots ,\tau _{i+p+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9bade620efa0080f5fd0dcb181009253d829c186.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:17.444ex; height:2.676ex;" alt="{\displaystyle {\bar {u}}=\tau _{i},\ldots ,\tau _{i+p+1}}" loading="lazy"></span>, solange <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3e6bb763d22c20916ed4f0bb6bd49d7470cffd8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle u}" loading="lazy"></span> kleiner <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/814ca8b33360ac3b7db8e9435271b5654175c853.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.816ex; height:2.009ex;" alt="{\displaystyle \tau _{i}}" loading="lazy"></span> bleibt. In diesem Bereich für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3e6bb763d22c20916ed4f0bb6bd49d7470cffd8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle u}" loading="lazy"></span> ergibt sich also eine dividierte Differenz vom Grad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5885ec01d3b5670fd5f88847f32da2b3dd62f60c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.262ex; height:2.509ex;" alt="{\displaystyle p+1}" loading="lazy"></span> für ein Polynom <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span>-ten Grades, die trivialerweise null ist.
Auf der anderen Seite ist für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u>\tau _{i+p+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u>\tau _{i+p+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/be42c08ff2121372a3586ec5391c373ed18eef3b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:10.45ex; height:2.509ex;" alt="{\displaystyle u>\tau _{i+p+1}}" loading="lazy"></span> die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle ({\bar {u}}-u)_{+}^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle ({\bar {u}}-u)_{+}^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7c85709cada9719c5ab0e1b2004a5f65e557532a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.82ex; height:3.176ex;" alt="{\displaystyle ({\bar {u}}-u)_{+}^{p}}" loading="lazy"></span> an allen für die dividierte Differenz auszuwertenden Stellen bei <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/60f3ac8e2b346a7087627be0542c3d305d0ea236.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.396ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)}" loading="lazy"></span> gleich null, womit dort ebenfalls <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/04189ba3400d5fda340fafd0e428d7f11131eaad.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.657ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)=0}" loading="lazy"></span> gilt.
</p><p>Der Träger von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/60f3ac8e2b346a7087627be0542c3d305d0ea236.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.396ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)}" loading="lazy"></span> liegt also innerhalb des Intervalls <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{i},\tau _{i+p+1}]}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">]</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{i},\tau _{i+p+1}]}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/647481d7dfc8c8b57e60b328bebabb52fbb24926.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:10.165ex; height:3.009ex;" alt="{\displaystyle [\tau _{i},\tau _{i+p+1}]}" loading="lazy"></span>.
</p><p>Unterscheiden sich die Stellen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/814ca8b33360ac3b7db8e9435271b5654175c853.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.816ex; height:2.009ex;" alt="{\displaystyle \tau _{i}}" loading="lazy"></span> alle voneinander, so ist die dividierte Differenz in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ab419832b622011aef27d5bdf41ae8a29da49edb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:5.257ex; height:2.843ex;" alt="{\displaystyle N_{i,p,\tau }}" loading="lazy"></span> eine endliche Linearkombination von Funktionen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\mapsto ({\bar {u}}-u)_{+}^{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo stretchy="false">↦<!-- ↦ --></mo>
<mo stretchy="false">(</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
<mo>−<!-- − --></mo>
<mi>u</mi>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mo>+</mo>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\mapsto ({\bar {u}}-u)_{+}^{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8df95a2e3abad661bcd78ef00a11a95b0740e595.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:13.764ex; height:3.176ex;" alt="{\displaystyle u\mapsto ({\bar {u}}-u)_{+}^{p}}" loading="lazy"></span> mit unterschiedlichen Werten für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\bar {u}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mi>u</mi>
<mo stretchy="false">¯<!-- ¯ --></mo>
</mover>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\bar {u}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3d707dfa8c7f2c1d6635efa659a22efb3c71e8f4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:2.009ex;" alt="{\displaystyle {\bar {u}}}" loading="lazy"></span> und als solche <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle (p-1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">(</mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle (p-1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ac90749c06d21ccfffb53161ea2ef2a9d7ef4e7e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.982ex; height:2.843ex;" alt="{\displaystyle (p-1)}" loading="lazy"></span>-mal stetig differenzierbar.
</p>
<div class="mw-heading mw-heading3"><h3 id="Eigenschaften">Eigenschaften</h3></div>
<p>Die folgenden Eigenschaften zeichnen die B-Splines <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ab419832b622011aef27d5bdf41ae8a29da49edb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:5.257ex; height:2.843ex;" alt="{\displaystyle N_{i,p,\tau }}" loading="lazy"></span> mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i=0,\ldots ,n-p-2}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i=0,\ldots ,n-p-2}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/55a121b8d73576965bb1f7f1ac65d25b4fb3d4c8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:19.649ex; height:2.509ex;" alt="{\displaystyle i=0,\ldots ,n-p-2}" loading="lazy"></span> im Raum der Splines <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle S_{p,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>S</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle S_{p,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/19043b56ac6a6c9e0f58e4b06e8a4f191b338afb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:3.791ex; height:2.843ex;" alt="{\displaystyle S_{p,\tau }}" loading="lazy"></span> mit Knotenvektor <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau =(\tau _{i})_{i=0}^{n-1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
<mo>=</mo>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<msubsup>
<mo stretchy="false">)</mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msubsup>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau =(\tau _{i})_{i=0}^{n-1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6e7f120b6467e2c5288e903045c35e596a09b3ab.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:11.245ex; height:3.343ex;" alt="{\displaystyle \tau =(\tau _{i})_{i=0}^{n-1}}" loading="lazy"></span> und Maximalgrad <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span> aus:
</p>
<ul><li>Nichtnegativität: <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)\geq 0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>≥<!-- ≥ --></mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)\geq 0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8c0ff247263ad13c4e511d2f72e0b7205c012959.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.657ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)\geq 0}" loading="lazy"></span></li>
<li>Lokaler Träger: <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)>0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>></mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)>0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ea84ad9e1d4a1de6fa4578964ca37814079d8a04.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.657ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)>0}" loading="lazy"></span>, falls <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\in {]\tau _{i},\tau _{i+p+1}[}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>∈<!-- ∈ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mo stretchy="false">]</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\in {]\tau _{i},\tau _{i+p+1}[}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3f70a9731d6eead5672954e4c13d0276ff9fce71.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:14.336ex; height:3.009ex;" alt="{\displaystyle u\in {]\tau _{i},\tau _{i+p+1}[}}" loading="lazy"></span>, und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)=0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)=0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/04189ba3400d5fda340fafd0e428d7f11131eaad.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.657ex; height:3.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)=0}" loading="lazy"></span>, falls <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\not \in [\tau _{i},\tau _{i+p+1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>∉</mo>
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\not \in [\tau _{i},\tau _{i+p+1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3413a51cead2fd7107bc27dc0942c0f42a2389f1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:14.336ex; height:3.009ex;" alt="{\displaystyle u\not \in [\tau _{i},\tau _{i+p+1}[}" loading="lazy"></span></li>
<li><a href="Zerlegung_der_Eins" title="Zerlegung der Eins">Zerlegung der Eins</a>: <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \sum _{i=0}^{n-p-2}N_{i,p,\tau }(u)=1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</munderover>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \sum _{i=0}^{n-p-2}N_{i,p,\tau }(u)=1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e208d2c1141d9d75c7934dc855c166af2dd9f50d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.005ex; width:18.237ex; height:7.343ex;" alt="{\displaystyle \sum _{i=0}^{n-p-2}N_{i,p,\tau }(u)=1}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>∈<!-- ∈ --></mo>
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f3c2b9310085cd0b4e084df400476050227c741b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:15.014ex; height:3.009ex;" alt="{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}" loading="lazy"></span></li></ul>
<div class="mw-heading mw-heading3"><h3 id="Effiziente_Berechnung">Effiziente Berechnung</h3></div>
<p>Die Basis-Splines können effektiv mit der Rekursionsformel von de Boor/Cox/Mansfield berechnet werden:<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,0,\tau }(u)={\begin{cases}1,&u\in \left[\tau _{i},\tau _{i+1}\right[\\0,&{\text{sonst}}\end{cases}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mn>0</mn>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mrow>
<mo>{</mo>
<mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false">
<mtr>
<mtd>
<mn>1</mn>
<mo>,</mo>
</mtd>
<mtd>
<mi>u</mi>
<mo>∈<!-- ∈ --></mo>
<mrow>
<mo>[</mo>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mrow>
<mo>[</mo>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<mn>0</mn>
<mo>,</mo>
</mtd>
<mtd>
<mrow class="MJX-TeXAtom-ORD">
<mtext>sonst</mtext>
</mrow>
</mtd>
</mtr>
</mtable>
<mo fence="true" stretchy="true" symmetric="true"></mo>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,0,\tau }(u)={\begin{cases}1,&u\in \left[\tau _{i},\tau _{i+1}\right[\\0,&{\text{sonst}}\end{cases}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3a8ba0ed0b1df474526be34c61cf586a25826edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:30.347ex; height:6.176ex;" alt="{\displaystyle N_{i,0,\tau }(u)={\begin{cases}1,&u\in \left[\tau _{i},\tau _{i+1}\right[\\0,&{\text{sonst}}\end{cases}}}" loading="lazy"></span></dd></dl>
<p>und
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }(u)={\frac {u-\tau _{i}}{\tau _{i+p}-\tau _{i}}}\,N_{i,p-1,\tau }(u)\;+\;{\frac {\tau _{i+p+1}-u}{\tau _{i+p+1}-\tau _{i+1}}}\,N_{i+1,p-1,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mrow>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mrow>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
<mspace width="thinmathspace"></mspace>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mspace width="thickmathspace"></mspace>
<mo>+</mo>
<mspace width="thickmathspace"></mspace>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<mi>u</mi>
</mrow>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
<mspace width="thinmathspace"></mspace>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
<mo>,</mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }(u)={\frac {u-\tau _{i}}{\tau _{i+p}-\tau _{i}}}\,N_{i,p-1,\tau }(u)\;+\;{\frac {\tau _{i+p+1}-u}{\tau _{i+p+1}-\tau _{i+1}}}\,N_{i+1,p-1,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e1fee70304055820623a3b33e02fcf54cda92e3a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:62.523ex; height:6.009ex;" alt="{\displaystyle N_{i,p,\tau }(u)={\frac {u-\tau _{i}}{\tau _{i+p}-\tau _{i}}}\,N_{i,p-1,\tau }(u)\;+\;{\frac {\tau _{i+p+1}-u}{\tau _{i+p+1}-\tau _{i+1}}}\,N_{i+1,p-1,\tau }(u)}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p>0}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>></mo>
<mn>0</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p>0}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8dffb51e20581d50c3012634fd9f7b059a68c1c4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.52ex; height:2.509ex;" alt="{\displaystyle p>0}" loading="lazy"></span>.</dd></dl>
<p>Die Elemente des Knotenvektors heißen auch Knotenpunkte (engl. <i>knots</i>) und müssen die Bedingungen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}\leq \tau _{i+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>≤<!-- ≤ --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}\leq \tau _{i+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6f22bbea69fb586d087c695ab3f66ee31cd9a3f5.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:8.831ex; height:2.343ex;" alt="{\displaystyle \tau _{i}\leq \tau _{i+1}}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}<\tau _{i+p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo><</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}<\tau _{i+p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ad0d73a931751e92a59bd3623dc8c9053ae6fb7b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.836ex; height:2.509ex;" alt="{\displaystyle \tau _{i}<\tau _{i+p}}" loading="lazy"></span> erfüllen.
</p><p>Zur Berechnung der <a href="Differentialrechnung" title="Differentialrechnung">Ableitung</a><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> eines B-Splines kann man obige Rekursionsformel mit der folgenden Vorschrift kombinieren:
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\frac {d}{du}}N_{i,p,\tau }(u)=N'_{i,p,\tau }(u)={\frac {p}{\tau _{i+p}-\tau _{i}}}N_{i,p-1,\tau }(u)-{\frac {p}{\tau _{i+p+1}-\tau _{i+1}}}N_{i+1,p-1,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mi>d</mi>
<mrow>
<mi>d</mi>
<mi>u</mi>
</mrow>
</mfrac>
</mrow>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<msubsup>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
<mo>′</mo>
</msubsup>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mi>p</mi>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>−<!-- − --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mi>p</mi>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
<mo>,</mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\frac {d}{du}}N_{i,p,\tau }(u)=N'_{i,p,\tau }(u)={\frac {p}{\tau _{i+p}-\tau _{i}}}N_{i,p-1,\tau }(u)-{\frac {p}{\tau _{i+p+1}-\tau _{i+1}}}N_{i+1,p-1,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/12d844b442d1b205fac7fc5906fb5fd8737f0f43.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:75.335ex; height:6.009ex;" alt="{\displaystyle {\frac {d}{du}}N_{i,p,\tau }(u)=N'_{i,p,\tau }(u)={\frac {p}{\tau _{i+p}-\tau _{i}}}N_{i,p-1,\tau }(u)-{\frac {p}{\tau _{i+p+1}-\tau _{i+1}}}N_{i+1,p-1,\tau }(u)}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p\geq 1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>≥<!-- ≥ --></mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p\geq 1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/cf93c1353080a21b276e79058d82c19c40310653.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.52ex; height:2.509ex;" alt="{\displaystyle p\geq 1}" loading="lazy"></span>.</dd></dl>
<p>Bemerkung:<br>
Die Bedingungen an die Knotenpunkte <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/814ca8b33360ac3b7db8e9435271b5654175c853.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.816ex; height:2.009ex;" alt="{\displaystyle \tau _{i}}" loading="lazy"></span> erlauben es, dass in der Rekursionsformel unter Umständen Null als Nenner auftritt (nämlich wenn <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i+p}=\tau _{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
<mo>=</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i+p}=\tau _{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/cca608c1a06cad7dd206d3a9d4f36f46a484fe05.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:8.836ex; height:2.343ex;" alt="{\displaystyle \tau _{i+p}=\tau _{i}}" loading="lazy"></span> bzw. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i+p+1}=\tau _{i+1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>=</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i+p+1}=\tau _{i+1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/aacbf3b1297a2f940b28ee3aceef27358596a3c8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:13.037ex; height:2.343ex;" alt="{\displaystyle \tau _{i+p+1}=\tau _{i+1}}" loading="lazy"></span> gilt).
Allerdings ist dann die Funktion <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i,p,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i,p,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ab419832b622011aef27d5bdf41ae8a29da49edb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:5.257ex; height:2.843ex;" alt="{\displaystyle N_{i,p,\tau }}" loading="lazy"></span> bzw. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle N_{i+1,p,\tau }}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle N_{i+1,p,\tau }}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/7d295047507b537d664c52e3de7f1fec71e4f4b7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:7.358ex; height:2.843ex;" alt="{\displaystyle N_{i+1,p,\tau }}" loading="lazy"></span> automatisch die <a href="Nullfunktion" title="Nullfunktion">Nullfunktion</a>.
Auf die entsprechende Fallunterscheidung wird hier verzichtet, man ignoriere die entsprechenden Summanden in diesen Fällen (ersetze sie durch Null). Dies entspricht auch dem Grenzverhalten für z. B. <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i+p}\to \tau _{i}.}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
<mo stretchy="false">→<!-- → --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>.</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i+p}\to \tau _{i}.}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9d5959806fb02619e627aaa827e5d3b2dc798401.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:9.998ex; height:2.509ex;" alt="{\displaystyle \tau _{i+p}\to \tau _{i}.}" loading="lazy"></span>
</p>
<div class="mw-heading mw-heading3"><h3 id="B-Spline-Kurve">B-Spline-Kurve</h3></div>
<p>Eine Spline-Kurve, deren Darstellung auf B-Splines beruht, nennt man <i>B-Spline-Kurve</i>. Bestimmt wird die Kurve durch sogenannte <i>De-Boor-Punkte</i>, mit denen sich das Aussehen der Kurve leicht steuern lässt: Die Kurve liegt immer in der <a href="Konvexe_H%C3%BClle" title="Konvexe Hülle">konvexen Hülle</a> der De-Boor-Punkte, wird also von ihnen eingeschlossen.
</p><p>Eine B-Spline-Kurve <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9e1a99bdb597accefb018ffb8889eae39a82108a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:4.905ex; height:2.843ex;" alt="{\displaystyle C(u)}" loading="lazy"></span>, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>∈<!-- ∈ --></mo>
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f3c2b9310085cd0b4e084df400476050227c741b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:15.014ex; height:3.009ex;" alt="{\displaystyle u\in [\tau _{p},\tau _{n-p-1}[}" loading="lazy"></span>, des Maximalgrads <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span> mit Knotenvektor <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> (s. o.) und Kontrollpunkten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{i}\ (i=0,\ldots ,n-p-2)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mtext> </mtext>
<mo stretchy="false">(</mo>
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{i}\ (i=0,\ldots ,n-p-2)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9ef96db27f0ff1a39c6fd22d27e5266476066482.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:24.331ex; height:2.843ex;" alt="{\displaystyle P_{i}\ (i=0,\ldots ,n-p-2)}" loading="lazy"></span> (auch <i>De-Boor-Punkte</i> genannt) wird definiert durch
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u)=\sum _{i=0}^{n-p-2}\;P_{i}\,N_{i,p,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</munderover>
<mspace width="thickmathspace"></mspace>
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mspace width="thinmathspace"></mspace>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u)=\sum _{i=0}^{n-p-2}\;P_{i}\,N_{i,p,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/fdd37b0eb0ca4961d5d8f9eb55428c23888d6fc1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.005ex; width:25.304ex; height:7.343ex;" alt="{\displaystyle C(u)=\sum _{i=0}^{n-p-2}\;P_{i}\,N_{i,p,\tau }(u)}" loading="lazy"></span>.</dd></dl>
<p>Für Kurven in der Ebene sind die Kontrollpunkte zweidimensional, für Kurven im Raum dreidimensional.
</p><p>Eigenschaften:
</p>
<ul><li>Lokalität: Der Kontrollpunkt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3ba1396129f7be3c7f828a571b6649e6807d10d3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.292ex; height:2.509ex;" alt="{\displaystyle P_{i}}" loading="lazy"></span> beeinflusst die Kurve nur im Intervall <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{i},\tau _{i+p+1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{i},\tau _{i+p+1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/bb394aed4c3de2291492ea392a51a0ae46760071.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:10.165ex; height:3.009ex;" alt="{\displaystyle [\tau _{i},\tau _{i+p+1}[}" loading="lazy"></span>.</li>
<li>Endpunkt-Interpolation: Es ist <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{0}=C(\tau _{p})}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>=</mo>
<mi>C</mi>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{0}=C(\tau _{p})}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/13861b033195113476a6577b83e65ac2f1d501ea.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:11.296ex; height:3.009ex;" alt="{\displaystyle P_{0}=C(\tau _{p})}" loading="lazy"></span>, falls die ersten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5885ec01d3b5670fd5f88847f32da2b3dd62f60c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.262ex; height:2.509ex;" alt="{\displaystyle p+1}" loading="lazy"></span> Knotenpunkte <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{0},\ldots ,\tau _{p}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{0},\ldots ,\tau _{p}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/8353378ff476e12586465147320942cae8b466e6.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:9.324ex; height:2.343ex;" alt="{\displaystyle \tau _{0},\ldots ,\tau _{p}}" loading="lazy"></span> gleich sind, und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{n-p-2}=C(\tau _{n-1-p})}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</msub>
<mo>=</mo>
<mi>C</mi>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>−<!-- − --></mo>
<mi>p</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{n-p-2}=C(\tau _{n-1-p})}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/54e340f2bab613e3d7873e61fe8438a5a2c95208.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:20.031ex; height:3.009ex;" alt="{\displaystyle P_{n-p-2}=C(\tau _{n-1-p})}" loading="lazy"></span>, falls die letzten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5885ec01d3b5670fd5f88847f32da2b3dd62f60c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.262ex; height:2.509ex;" alt="{\displaystyle p+1}" loading="lazy"></span> Knotenpunkte <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{n-1-p},\ldots ,\tau _{n-1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>−<!-- − --></mo>
<mi>p</mi>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{n-1-p},\ldots ,\tau _{n-1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/899df001adb2200cc15fa6ac243d2b8208e4856a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:15.954ex; height:2.343ex;" alt="{\displaystyle \tau _{n-1-p},\ldots ,\tau _{n-1}}" loading="lazy"></span> gleich sind.</li></ul>
<p>Eine ähnliche Darstellung haben <a href="B%C3%A9zierkurve" title="Bézierkurve">Bézierkurven</a>. Diese basieren nicht auf der oben genannten Basis, sondern auf den <a href="Bernsteinpolynom" title="Bernsteinpolynom">Bernsteinpolynomen</a>. Genau wie bei B-Spline-Kurven die De-Boor-Punkte gibt es hier die Bézier-Punkte, die das sogenannte Kontrollpolygon bilden und mit denen man die Kurve leicht graphisch darstellen kann.
</p><p>Einen einfachen Zusammenhang von <a href="B%C3%A9zierkurve" title="Bézierkurve">Bézierkurven</a> und B-Spline-Kurven in Verbindung mit einer einfachen Berechnung stellt das <a href="Blossoming" title="Blossoming">Blossoming</a> dar, welches von <a href="Paul_de_Faget_de_Casteljau" class="mw-redirect" title="Paul de Faget de Casteljau">Paul de Faget de Casteljau</a> Anfang der 1980er-Jahre entdeckt und von Lyle Ramshaw verbreitet wurde.
</p>
<div class="mw-heading mw-heading3"><h3 id="Algorithmus_von_de_Boor">Algorithmus von de Boor</h3></div>
<p>Statt der Gleichung in obiger Definition für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9e1a99bdb597accefb018ffb8889eae39a82108a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:4.905ex; height:2.843ex;" alt="{\displaystyle C(u)}" loading="lazy"></span> wird zur effizienten Berechnung von B-Spline-Kurven <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9e1a99bdb597accefb018ffb8889eae39a82108a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:4.905ex; height:2.843ex;" alt="{\displaystyle C(u)}" loading="lazy"></span> mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3e6bb763d22c20916ed4f0bb6bd49d7470cffd8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle u}" loading="lazy"></span> im Intervall <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{p},\tau _{n-p-1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{p},\tau _{n-p-1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/1c36c77ae0f9258a56eca830bd801940974778d1.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:10.844ex; height:3.009ex;" alt="{\displaystyle [\tau _{p},\tau _{n-p-1}[}" loading="lazy"></span> meist der im Folgenden beschriebene Algorithmus von De Boor verwendet.
</p>
<pre>1. Suche <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i\in \{0,\ldots ,n-p-2\}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
<mo>∈<!-- ∈ --></mo>
<mo fence="false" stretchy="false">{</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mo fence="false" stretchy="false">}</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i\in \{0,\ldots ,n-p-2\}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5bf5669eaa820d53f751d9ceaf0a317e84139e72.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:21.716ex; height:2.843ex;" alt="{\displaystyle i\in \{0,\ldots ,n-p-2\}}" loading="lazy"></span>, so dass <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u\in [\tau _{i},\tau _{i+1}[}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
<mo>∈<!-- ∈ --></mo>
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">[</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u\in [\tau _{i},\tau _{i+1}[}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3a7cd46d215c0b60912a69dbab6a9cc556ad9a4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:12.23ex; height:2.843ex;" alt="{\displaystyle u\in [\tau _{i},\tau _{i+1}[}" loading="lazy"></span> gilt.
Gibt es keinen solchen Index <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>i</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle i}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/add78d8608ad86e54951b8c8bd6c8d8416533d20.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.802ex; height:2.176ex;" alt="{\displaystyle i}" loading="lazy"></span>, so liegt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3e6bb763d22c20916ed4f0bb6bd49d7470cffd8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle u}" loading="lazy"></span> außerhalb des Definitionsbereiches der Splinekurve <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4fc55753007cd3c18576f7933f6f089196732029.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.766ex; height:2.176ex;" alt="{\displaystyle C}" loading="lazy"></span>,
und es muss extrapoliert oder eine Fehlermeldung ausgegeben werden.
2. Initialisiere Hilfsgrößen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q_{0,j}:=P_{i+j}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>:=</mo>
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q_{0,j}:=P_{i+j}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/55812be4b6d499d9c5d8123ae4c99378079aa56a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:11.219ex; height:2.843ex;" alt="{\displaystyle q_{0,j}:=P_{i+j}}" loading="lazy"></span> für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle j=0,\ldots ,d}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>j</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle j=0,\ldots ,d}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/fbffe7c4167958580f532473b923003f07804e05.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.027ex; width:11.64ex; height:2.509ex;" alt="{\displaystyle j=0,\ldots ,d}" loading="lazy"></span>
3. Führe für <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle l=1,\ldots ,d}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>l</mi>
<mo>=</mo>
<mn>1</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle l=1,\ldots ,d}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/50cda9bb1ac2e6b92a785bb8fc26292396a1e92d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:11.348ex; height:2.509ex;" alt="{\displaystyle l=1,\ldots ,d}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle j=0,\ldots ,d-l}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>j</mi>
<mo>=</mo>
<mn>0</mn>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<mi>d</mi>
<mo>−<!-- − --></mo>
<mi>l</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle j=0,\ldots ,d-l}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f56b83636cc1469c97336beb19c15b43084044cb.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.027ex; width:15.173ex; height:2.509ex;" alt="{\displaystyle j=0,\ldots ,d-l}" loading="lazy"></span> folgende Teilschritte 3.1 bis 3.3 iterativ aus:
3.1. Im Ausnahmefall gleicher Knoten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i+j}=\tau _{i+j+l}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>=</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
<mo>+</mo>
<mi>l</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i+j}=\tau _{i+j+l}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ad9fd258897a0d39327989cfe2f751ff3f866680.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.411ex; height:2.343ex;" alt="{\displaystyle \tau _{i+j}=\tau _{i+j+l}}" loading="lazy"></span> setze <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q_{l,j}:=q_{l-1,j}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>:=</mo>
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q_{l,j}:=q_{l-1,j}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/fe393434c418fe06f9b4dd55e9b1f56b9b749f97.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:11.635ex; height:2.343ex;" alt="{\displaystyle q_{l,j}:=q_{l-1,j}}" loading="lazy"></span> und fahre mit dem nächsten Iterationsschritt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle j:=j+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>j</mi>
<mo>:=</mo>
<mi>j</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle j:=j+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/004ab15557c8544248401f5d4767a6d0f4aeec1d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.027ex; width:9.691ex; height:2.509ex;" alt="{\displaystyle j:=j+1}" loading="lazy"></span> bei 3.1. fort.
3.2. Gilt dagegen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{i+j}<\tau _{i+j+l}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
</mrow>
</msub>
<mo><</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
<mo>+</mo>
<mi>l</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau _{i+j}<\tau _{i+j+l}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/b0a0cf78e1ba47d0e048c19a3010f51607d1875d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.411ex; height:2.509ex;" alt="{\displaystyle \tau _{i+j}<\tau _{i+j+l}}" loading="lazy"></span>, so berechne <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \alpha _{l,j}:={\frac {u-\tau _{i+j}}{\tau _{i+j+l}-\tau _{i+j}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>α<!-- α --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>:=</mo>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mrow>
<mi>u</mi>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
</mrow>
</msub>
</mrow>
<mrow>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
<mo>+</mo>
<mi>l</mi>
</mrow>
</msub>
<mo>−<!-- − --></mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>j</mi>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \alpha _{l,j}:={\frac {u-\tau _{i+j}}{\tau _{i+j+l}-\tau _{i+j}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e9df2f701a6f27af410a9369a5e6fa8dbfe760f3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:20.079ex; height:6.009ex;" alt="{\displaystyle \alpha _{l,j}:={\frac {u-\tau _{i+j}}{\tau _{i+j+l}-\tau _{i+j}}}}" loading="lazy"></span>.
3.3. Berechne damit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q_{l,j}:=q_{l-1,j}\cdot (1-\alpha _{l,j})+q_{l-1,j+1}\cdot \alpha _{l,j}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>:=</mo>
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<mo stretchy="false">(</mo>
<mn>1</mn>
<mo>−<!-- − --></mo>
<msub>
<mi>α<!-- α --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mo>+</mo>
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>,</mo>
<mi>j</mi>
<mo>+</mo>
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>α<!-- α --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>l</mi>
<mo>,</mo>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q_{l,j}:=q_{l-1,j}\cdot (1-\alpha _{l,j})+q_{l-1,j+1}\cdot \alpha _{l,j}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c13a0be1fcf23348592b445881e8cd7e417a17e8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:37.431ex; height:3.009ex;" alt="{\displaystyle q_{l,j}:=q_{l-1,j}\cdot (1-\alpha _{l,j})+q_{l-1,j+1}\cdot \alpha _{l,j}}" loading="lazy"></span>.
4. Als Endergebnis der Iteration erhält man <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u):=q_{d,0}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>:=</mo>
<msub>
<mi>q</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>d</mi>
<mo>,</mo>
<mn>0</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u):=q_{d,0}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/88ccbc6766afc77365cb1f88fb97c39f6605133f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:12.059ex; height:3.009ex;" alt="{\displaystyle C(u):=q_{d,0}}" loading="lazy"></span>.
</pre>
<p>Sind mehrere Splines, die sich nur durch die Koeffizienten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{i}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{i}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/3ba1396129f7be3c7f828a571b6649e6807d10d3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.292ex; height:2.509ex;" alt="{\displaystyle P_{i}}" loading="lazy"></span> unterscheiden, an derselben Stelle <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle u}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle u}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c3e6bb763d22c20916ed4f0bb6bd49d7470cffd8.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle u}" loading="lazy"></span> auszuwerten, so kann die in der Definition der B-Spline-Kurve aufgeführte Berechnungsvorschrift <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u)=\sum _{i=0}^{n-p-2}P_{i}N_{i,p,\tau }(u)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
</mrow>
</munderover>
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u)=\sum _{i=0}^{n-p-2}P_{i}N_{i,p,\tau }(u)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/6e1e06cd5b2de16cc1b34c94464c79ac39d57d54.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.005ex; width:24.271ex; height:7.343ex;" alt="{\displaystyle C(u)=\sum _{i=0}^{n-p-2}P_{i}N_{i,p,\tau }(u)}" loading="lazy"></span> effizienter als der Algorithmus von de Boor sein.
</p>
<div class="mw-heading mw-heading3"><h3 id="B-Spline-Fläche"><span id="B-Spline-Fl.C3.A4che"></span>B-Spline-Fläche</h3></div>
<p>Eine B-Spline-Fläche der Maximalgrade <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/81eac1e205430d1f40810df36a0edffdc367af36.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:1.259ex; height:2.009ex;" alt="{\displaystyle p}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>q</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/06809d64fa7c817ffc7e323f85997f783dbdf71d.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:1.07ex; height:2.009ex;" alt="{\displaystyle q}" loading="lazy"></span> in der ersten beziehungsweise zweiten Variablen mit Knotenvektoren <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\ (n\geq 2p+1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
<mo>=</mo>
<mo stretchy="false">(</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mtext> </mtext>
<mo stretchy="false">(</mo>
<mi>n</mi>
<mo>≥<!-- ≥ --></mo>
<mn>2</mn>
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\ (n\geq 2p+1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/c482c29d6c49a56d2c71e29b1628bc87bd2059df.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:30.911ex; height:2.843ex;" alt="{\displaystyle \tau =(\tau _{0},\ldots ,\tau _{n-1})\ (n\geq 2p+1)}" loading="lazy"></span> und <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mu =(\mu _{0},\ldots ,\mu _{m-1})\ (m\geq 2q+1)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>μ<!-- μ --></mi>
<mo>=</mo>
<mo stretchy="false">(</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>0</mn>
</mrow>
</msub>
<mo>,</mo>
<mo>…<!-- … --></mo>
<mo>,</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>m</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
</mrow>
</msub>
<mo stretchy="false">)</mo>
<mtext> </mtext>
<mo stretchy="false">(</mo>
<mi>m</mi>
<mo>≥<!-- ≥ --></mo>
<mn>2</mn>
<mi>q</mi>
<mo>+</mo>
<mn>1</mn>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \mu =(\mu _{0},\ldots ,\mu _{m-1})\ (m\geq 2q+1)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f73ae9d278b41d77604ec40e853c285f125a1741.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:32.884ex; height:2.843ex;" alt="{\displaystyle \mu =(\mu _{0},\ldots ,\mu _{m-1})\ (m\geq 2q+1)}" loading="lazy"></span> und Kontrollpunkten (bzw. <i>De Boor Punkten</i>) <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{ij}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{ij}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/43ef37c239b6d38f1e951a31eb1a3bd295271b40.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:2.969ex; height:2.843ex;" alt="{\displaystyle P_{ij}}" loading="lazy"></span> wird definiert durch
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle C(u,v)=\sum _{i=0}^{\ n-p-2\ }\sum _{j=0}^{\ m-q-2\ }\;P_{ij}\,N_{i,p,\tau }(u)\,N_{j,q,\mu }(v)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>C</mi>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo>,</mo>
<mi>v</mi>
<mo stretchy="false">)</mo>
<mo>=</mo>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mtext> </mtext>
<mi>n</mi>
<mo>−<!-- − --></mo>
<mi>p</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mtext> </mtext>
</mrow>
</munderover>
<munderover>
<mo>∑<!-- ∑ --></mo>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow class="MJX-TeXAtom-ORD">
<mtext> </mtext>
<mi>m</mi>
<mo>−<!-- − --></mo>
<mi>q</mi>
<mo>−<!-- − --></mo>
<mn>2</mn>
<mtext> </mtext>
</mrow>
</munderover>
<mspace width="thickmathspace"></mspace>
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mi>j</mi>
</mrow>
</msub>
<mspace width="thinmathspace"></mspace>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>,</mo>
<mi>p</mi>
<mo>,</mo>
<mi>τ<!-- τ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>u</mi>
<mo stretchy="false">)</mo>
<mspace width="thinmathspace"></mspace>
<msub>
<mi>N</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
<mo>,</mo>
<mi>q</mi>
<mo>,</mo>
<mi>μ<!-- μ --></mi>
</mrow>
</msub>
<mo stretchy="false">(</mo>
<mi>v</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle C(u,v)=\sum _{i=0}^{\ n-p-2\ }\sum _{j=0}^{\ m-q-2\ }\;P_{ij}\,N_{i,p,\tau }(u)\,N_{j,q,\mu }(v)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ab5b1ab2cac8d85d35dba518eeb6a4d9d920d9dd.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.338ex; width:45.193ex; height:7.676ex;" alt="{\displaystyle C(u,v)=\sum _{i=0}^{\ n-p-2\ }\sum _{j=0}^{\ m-q-2\ }\;P_{ij}\,N_{i,p,\tau }(u)\,N_{j,q,\mu }(v)}" loading="lazy"></span></dd></dl>
<p>Die Fläche ist definiert über dem Rechteck <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{p},\tau _{n-1-p}]\times [\mu _{q},\mu _{m-1-q}]}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>p</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>n</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>−<!-- − --></mo>
<mi>p</mi>
</mrow>
</msub>
<mo stretchy="false">]</mo>
<mo>×<!-- × --></mo>
<mo stretchy="false">[</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>q</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>m</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
<mo>−<!-- − --></mo>
<mi>q</mi>
</mrow>
</msub>
<mo stretchy="false">]</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{p},\tau _{n-1-p}]\times [\mu _{q},\mu _{m-1-q}]}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/bb9f29b71e02b677f88b135c496363d1251bdadd.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:25.614ex; height:3.009ex;" alt="{\displaystyle [\tau _{p},\tau _{n-1-p}]\times [\mu _{q},\mu _{m-1-q}]}" loading="lazy"></span>.
</p><p>Eigenschaften:
</p>
<ul><li>Lokalität: Der Kontrollpunkt <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{ij}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mi>j</mi>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle P_{ij}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/43ef37c239b6d38f1e951a31eb1a3bd295271b40.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:2.969ex; height:2.843ex;" alt="{\displaystyle P_{ij}}" loading="lazy"></span> beeinflusst die Fläche nur im Rechteck <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle [\tau _{i},\tau _{i+p}]\times [\mu _{j},\mu _{j+q}]}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo stretchy="false">[</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>τ<!-- τ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>i</mi>
<mo>+</mo>
<mi>p</mi>
</mrow>
</msub>
<mo stretchy="false">]</mo>
<mo>×<!-- × --></mo>
<mo stretchy="false">[</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
</mrow>
</msub>
<mo>,</mo>
<msub>
<mi>μ<!-- μ --></mi>
<mrow class="MJX-TeXAtom-ORD">
<mi>j</mi>
<mo>+</mo>
<mi>q</mi>
</mrow>
</msub>
<mo stretchy="false">]</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle [\tau _{i},\tau _{i+p}]\times [\mu _{j},\mu _{j+q}]}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/56f4f11e7393939ea713fa9b90b5faf6844ca952.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:19.89ex; height:3.009ex;" alt="{\displaystyle [\tau _{i},\tau _{i+p}]\times [\mu _{j},\mu _{j+q}]}" loading="lazy"></span></li>
<li>Endpunktinterpolation: Werden die ersten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5885ec01d3b5670fd5f88847f32da2b3dd62f60c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.262ex; height:2.509ex;" alt="{\displaystyle p+1}" loading="lazy"></span> Knotenpunkte in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> auf den gleichen Wert gesetzt, die letzten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle p+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>p</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle p+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5885ec01d3b5670fd5f88847f32da2b3dd62f60c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-left: -0.089ex; width:5.262ex; height:2.509ex;" alt="{\displaystyle p+1}" loading="lazy"></span> Knotenpunkte in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>τ<!-- τ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \tau }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/38a7dcde9730ef0853809fefc18d88771f95206c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.202ex; height:1.676ex;" alt="{\displaystyle \tau }" loading="lazy"></span> auf den gleichen Wert gesetzt, die ersten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>q</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q+1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/738ec5afa1574426d17dad902eeb361faaa57342.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:5.072ex; height:2.509ex;" alt="{\displaystyle q+1}" loading="lazy"></span> Knotenpunkte in <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mu }">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>μ<!-- μ --></mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \mu }</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9fd47b2a39f7a7856952afec1f1db72c67af6161.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:1.402ex; height:2.176ex;" alt="{\displaystyle \mu }" loading="lazy"></span> auf den gleichen Wert gesetzt und die letzten <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle q+1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>q</mi>
<mo>+</mo>
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle q+1}</annotation>
</semantics>
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<annotation encoding="application/x-tex">{\displaystyle P_{0,0}=C(\tau _{p},\mu _{q})}</annotation>
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</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/23bcf7a293cb6f97bc2747a80189e1825f21b238.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.005ex; width:15.999ex; height:3.009ex;" alt="{\displaystyle P_{0,0}=C(\tau _{p},\mu _{q})}" loading="lazy"></span>, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P_{0,m-q-2}=C(\tau _{p},\mu _{m-1-q})}">
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
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<annotation encoding="application/x-tex">{\displaystyle P_{0,m-q-2}=C(\tau _{p},\mu _{m-1-q})}</annotation>
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>P</mi>
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<annotation encoding="application/x-tex">{\displaystyle P_{n-p-2,0}=C(\tau _{n-1-p},\mu _{q})}</annotation>
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
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<div class="mw-heading mw-heading2"><h2 id="Weitere_Varianten_und_Verallgemeinerungen">Weitere Varianten und Verallgemeinerungen</h2></div>
<p>Neben den B-Splines gibt es weitere Varianten von Splines, beispielsweise den <a href="Kubisch_Hermitescher_Spline" title="Kubisch Hermitescher Spline">kubisch hermiteschen Spline</a>.
Eine Verallgemeinerung von Splines sind <a href="Non-Uniform_Rational_B-Spline" title="Non-Uniform Rational B-Spline">NURBS</a>, die durch stückweise rationale Funktionen anstelle von Polynomen beschrieben werden. Mit NURBS-Kurven sind Kreise exakt darstellbar.
</p>
<div class="mw-heading mw-heading2"><h2 id="Literatur">Literatur</h2></div>
<ul><li>Andrew Blake and Michael Isard: "Active Contours". Springer Verlag, 1998, ISBN 978-1-4471-1555-7</li>
<li>Carl de Boor: <i>A Practical Guide to Splines</i>. Springer Verlag, New York 1978, ISBN 0-387-90356-9 und ISBN 3-540-90356-9 (Rev. Auf.. 2001 ISBN 0-387-95366-3)</li>
<li>Paul de Faget de Casteljau: <i>Formes à Pôles</i>. Hermès, Paris 1985, ISBN 2-86601-044-2</li>
<li>Gerald Farin: <i>Curves and Surfaces for CAGD. A practical guide.</i> 5. Aufl. Academic Press, San Diego 2002, ISBN 1-55860-737-4</li>
<li>Günther Nürnberger: <i>Approximation by Spline Functions.</i> Springer Verlag, 1989, ISBN 3-540-51618-2 und ISBN 0-387-51618-2</li>
<li>Hartmut Prautzsch, Wolfgang Böhm, Marco Paluszny: <i>Bezier and B-Spline Techniques</i>. Springer Verlag, Berlin 2001, ISBN 3-540-43761-4</li>
<li>David Salomon: <i>Curves and Surfaces for Computer Graphics</i>. 2006 Springer Science+Business Media, Inc.; ISBN 0-387-24196-5</li>
<li>Isaac Jacob Schoenberg: <i>Contributions to the problem of approximation of equidistant data by analytic functions</i>. Quart. Appl. Math., vol. 4, S. 45–99 und 112–141, 1946.</li>
<li><a href="Martin_Hermann_(Mathematiker)" title="Martin Hermann (Mathematiker)">Martin Hermann:</a> <i>Numerische Mathematik, Band 2: Analytische Probleme</i>. 4., überarbeitete und erweiterte Auflage. Walter de Gruyter Verlag, Berlin und Boston 2020, ISBN 978-3-11-065765-4.</li></ul>
<div class="mw-heading mw-heading2"><h2 id="Weblinks">Weblinks</h2></div>
<ul><li><a rel="nofollow" class="external text" href="https://lp.uni-goettingen.de/get/text/1234">LP – Räume von Spline-Funktionen</a></li>
<li><a rel="nofollow" class="external text" href="http://userpage.fu-berlin.de/~vratisla/Bildverarbeitung/Bspline/Bspline.html">Java-Applet zum Berechnen von B-Spline-Kurven</a></li>
<li><a rel="nofollow" class="external text" href="http://www.arndt-bruenner.de/mathe/scripts/kubspline.htm">Website mit Erklärungen und Tool zur Berechnung von kubischen Splines</a></li>
<li><a rel="nofollow" class="external text" href="https://github.com/msteinbeck/tinyspline">TinySpline: Open Source C-Programmbibliothek für NURBS, B-Splines und Bezier Splines mit Bindings für verschiedene Sprachen</a></li></ul>
<div class="mw-heading mw-heading2"><h2 id="Einzelnachweise">Einzelnachweise</h2></div>
<ol class="references">
<li id="cite_note-1"><span class="mw-cite-backlink"><a href="#cite_ref-1">↑</a></span> <span class="reference-text">De Boor C. (1993): B(asic)–spline basics. In: Piegl L. (ed.): Fundamental Developments of Computer-Aided Geometric Modelling. Academic Press, San Diego, 27–49.</span>
</li>
<li id="cite_note-2"><span class="mw-cite-backlink"><a href="#cite_ref-2">↑</a></span> <span class="reference-text">Carl de Boor: A Practical Guide to Splines. Springer Verlag Berlin, 2001</span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><a href="#cite_ref-3">↑</a></span> <span class="reference-text"><span class="cite"><a rel="nofollow" class="external text" href="https://pages.mtu.edu/~shene/COURSES/cs3621/NOTES/spline/B-spline/bspline-basis.html"><i>B-spline Basis Functions: Definition.</i></a> In: <i>Michigan Technological University.</i><span class="Abrufdatum"> Abgerufen am 6. Februar 2023</span> (englisch).</span><span style="display: none;" class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2Fde.wikipedia.org%3ASpline&rft.title=B-spline+Basis+Functions%3A+Definition&rft.description=B-spline+Basis+Functions%3A+Definition&rft.identifier=https%3A%2F%2Fpages.mtu.edu%2F%7Eshene%2FCOURSES%2Fcs3621%2FNOTES%2Fspline%2FB-spline%2Fbspline-basis.html&rft.language=en"> </span></span>
</li>
<li id="cite_note-4"><span class="mw-cite-backlink"><a href="#cite_ref-4">↑</a></span> <span class="reference-text"><span class="cite"><a rel="nofollow" class="external text" href="https://pages.mtu.edu/~shene/COURSES/cs3621/NOTES/spline/B-spline/bspline-derv.html"><i>Derivatives of a B-spline Curve.</i></a> In: <i>Michigan Technological University.</i><span class="Abrufdatum"> Abgerufen am 6. Februar 2023</span> (englisch).</span><span style="display: none;" class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2Fde.wikipedia.org%3ASpline&rft.title=Derivatives+of+a+B-spline+Curve&rft.description=Derivatives+of+a+B-spline+Curve&rft.identifier=https%3A%2F%2Fpages.mtu.edu%2F%7Eshene%2FCOURSES%2Fcs3621%2FNOTES%2Fspline%2FB-spline%2Fbspline-derv.html&rft.language=en"> </span></span>
</li>
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