<?xml version="1.0" encoding="UTF-8"?>
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 * Scilab ( https://www.scilab.org/ ) - This file is part of Scilab
 * Copyright (C) 2008 - INRIA
 *
 * Copyright (C) 2012 - 2016 - Scilab Enterprises
 *
 * This file is hereby licensed under the terms of the GNU GPL v2.0,
 * pursuant to article 5.3.4 of the CeCILL v.2.1.
 * This file was originally licensed under the terms of the CeCILL v2.1,
 * and continues to be available under such terms.
 * For more information, see the COPYING file which you should have received
 * along with this program.
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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="trfmod">
    <refnamediv>
        <refname>trfmod</refname>
        <refpurpose>poles and zeros display</refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>Syntax</title>
        <synopsis>[hm]=trfmod(h [,job])</synopsis>
    </refsynopsisdiv>
    <refsection>
        <title>Description</title>
        <para>
            To visualize the pole-zero structure of a SISO transfer
            function <literal>h</literal> .
        </para>
        <variablelist>
            <varlistentry>
                <term>job='p'</term>
                <listitem>
                    <para>visualization of polynomials (default)</para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>job='f'</term>
                <listitem>
                    <para>visualization of natural frequencies and damping</para>
                </listitem>
            </varlistentry>
        </variablelist>
        <para>
            Interactive simplification of <literal>h</literal>. <literal>trfmod</literal> opens
            a dialog window.
        </para>
    </refsection>
    <refsection>
        <title>Examples</title>
        <programlisting role="example"><![CDATA[
// with a transfer function
s=poly(0,'s');
gs=syslin('c',1/(s+1));
trfmod(gs)

// with a state-space matrix
A=diag([1,2,3]);
B=[1;1;1];
C=[2,2,2];
sys=syslin('c',A,B,C);
trfmod(sys)
 ]]></programlisting>
    </refsection>

    <refsection role="see also">
        <title>See also</title>
        <simplelist type="inline">
            <member>
                <link linkend="poly">poly</link>
            </member>
            <member>
                <link linkend="simp">simp</link>
            </member>
        </simplelist>
    </refsection>
</refentry>
