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<?xml version="1.0" encoding="UTF-8"?>
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* Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
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* Copyright (C) 2008 - INRIA
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* This file must be used under the terms of the CeCILL.
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* This source file is licensed as described in the file COPYING, which
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* you should have received as part of this distribution. The terms
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* are also available at
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* http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
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<refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" version="5.0-subset Scilab" xml:lang="fr" xml:id="nlev">
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<refname>nlev</refname>
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<refpurpose> Algorithme de Leverrier </refpurpose>
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<title>Séquence d'appel</title>
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<synopsis>[num,den]=nlev(A,z [,rmax])</synopsis>
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<title>Paramètres</title>
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<para>matrice réelle carrée
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<para>chaîne de caractères
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paramètre optionnel (voir <literal>bdiag</literal>)
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<title>Description</title>
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<literal>[num,den]=nlev(A,z [,rmax])</literal> calcule
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<literal>(z*eye()-A)^(-1)</literal> par bloc diagonalisation de
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<literal>A</literal> suivie de l'algorithme de Leverrier sur chaque
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Cet algorithme est plus efficace que l'algorithme de
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Leverrier seul, mais il n'est toujours pas parfait !
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<title>Exemples</title>
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<programlisting role="example"><![CDATA[
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A=rand(3,3);x=poly(0,'x');
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clean(den-poly(A,'x'))
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clean(NUM/den-inv(x*eye()-A))
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<refsection role="see also">
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<title>Voir aussi</title>
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<simplelist type="inline">
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<link linkend="coff">coff</link>
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<link linkend="coffg">coffg</link>
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<link linkend="glever">glever</link>
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<link linkend="ss2tf">ss2tf</link>