<?xml version="1.0" encoding="UTF-8"?>
<refentry version="5.0-subset Scilab" xml:id="sp_cgne" xml:lang="en"
          xmlns="http://docbook.org/ns/docbook"
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          xmlns:db="http://docbook.org/ns/docbook">
  <info>
    <pubdate>$LastChangedDate: 2009-09-16 $</pubdate>
  </info>

  <refnamediv>
    <refname>sp_cgs</refname>

    <refpurpose>Use a conjugate gradient for a normal equation to solve the system A.x = b</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <title>Calling Sequence</title>

    <synopsis>[xsol[,iter]] = sp_cgne(A,b,tol[,maxit[,M[,x0]]])</synopsis>
  </refsynopsisdiv>

  <refsection>
    <title>Parameters</title>

    <variablelist>
      <varlistentry>
        <term>A</term>

        <listitem>
          <para>the A real sparse matrix of the system to be solved.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>b</term>

        <listitem>
          <para>the b real vector of the system to be solved.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>tol</term>

        <listitem>
          <para>the tolerance for the resolution of the equation system.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>maxit</term>

        <listitem>
          <para>the maximum number of iteration of the solver.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>M</term>

        <listitem>
          <para>the preconditionning matrix (an identity matrix by
          default). The preconditionning matrix must be symmetric.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>x0</term>

        <listitem>
          <para>an initial starting solution.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>xsol</term>

        <listitem>
          <para>the solution vector of the system.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>iter</term>

        <listitem>
          <para>the number of iterations performed to solve the system.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsection>

  <refsection>
    <title>Description</title>

    <para>Use a conjugate gradient for a normal equation to solve the system A.x = b</para>
  </refsection>

  <refsection>
    <title>Example</title>

    <programlisting role="example"><![CDATA[ 
 ]]></programlisting>
  </refsection>

  <refsection>
    <title>See Also</title>

    <simplelist type="inline">
      <member><link linkend="sp_luinc">sp_luinc</link></member>
      <member><link linkend="sp_chol">sp_chol</link></member>
      <member><link linkend="sp_cholinc">sp_cholinc</link></member>
      <member><link linkend="sp_lu">sp_lu</link></member>
      <member><link linkend="sp_cgs">sp_cgs</link></member>
      <member><link linkend="sp_gmres">sp_gmres</link></member>
      <member><link linkend="sp_mgcr">sp_mgcr</link></member>
      <member><link linkend="sp_chsolve">sp_chsolve</link></member>
      <member><link linkend="sp_lusolve">sp_lusolve</link></member>
    </simplelist>
  </refsection>

  <refsection>
    <title>Authors</title>

    <simplelist type="vert">
      <member>Yann COLLETTE</member>
    </simplelist>
  </refsection>
</refentry>
