<?xml version="1.0" encoding="UTF-8"?>
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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" xmlns:scilab="http://www.scilab.org"
          xml:lang="en" xml:id="nehari">
    <refnamediv>
        <refname>nehari</refname>
        <refpurpose>Nehari approximant of continuous time dynamical systems</refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>Syntax</title>
        <synopsis>
            x = nehari(R)
            x = nehari(R, tol)
        </synopsis>
    </refsynopsisdiv>
    <refsection>
        <title>Arguments</title>
        <variablelist>
            <varlistentry>
                <term>R</term>
                <listitem>
                    <para>a continuous time linear dynamical system in state-space representation.</para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>x</term>
                <listitem>
                    <para>a continuous time linear dynamical system in state-space representation.</para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>tol</term>
                <listitem>
                    <para>optional threshold, default value is 1e-6.</para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsection>
    <refsection>
        <title>Description</title>
        <para>
            <literal>[x]=nehari(R [,tol])returns</literal> the Nehari approximant of <literal>R</literal>.
        </para>
        <para>
            <literal>R</literal> = linear system in state-space representation (<literal>syslin</literal> list).
        </para>
        <para>
            <literal>R</literal> is strictly proper and <literal>- R~</literal> is stable
            (i.e. <literal>R</literal> is anti stable).
        </para>
        <programlisting role="no-scilab-exec"><![CDATA[
|| R - X ||oo = min || R - Y ||oo
              Y in Hoo
 ]]></programlisting>
    </refsection>
    <refsection>
        <title>History</title>
        <revhistory>
            <revision>
                <revnumber>5.4.0</revnumber>
                <revremark>
                    <literal>Sl</literal> is now checked for
                    continuous time linear dynamical system.  This modification
                    has been introduced by this <ulink url="http://gitweb.scilab.org/?p=scilab.git;a=commit;h=3d7083daae3339813ba747c8adcda1f9599bb80d">commit</ulink>
                </revremark>
            </revision>
        </revhistory>
    </refsection>
</refentry>
