<?xml version="1.0" encoding="UTF-8"?>
<!--
 * Scilab ( https://www.scilab.org/ ) - This file is part of Scilab
 * Copyright (C) 2016 - Serge Steer - INRIA
 *
 * 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.
 * For more information, see the COPYING file which you should have received
 * along with this program.
 *
 -->
<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="zpk2tf">
    <refnamediv>
        <refname>zpk2tf</refname>
        <refpurpose>Zero pole gain to transfer function</refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>Syntax</title>
        <synopsis>S = zpk2tf(sys)</synopsis>
    </refsynopsisdiv>
    <refsection>
        <title>Arguments</title>
        <variablelist>
            <varlistentry>
                <term>sys</term>
                <listitem>
                    <para>
                        A linear dynamical system in zero-pole-gain  representation (see
                        <link linkend="zpk">zpk</link>).
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>S</term>
                <listitem>
                    <para>
                        The rational transfer function representation of sys.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsection>
    <refsection>
        <title>Description</title>
        <para>
            Converts a  zero pole gain representation to  rational transfer function
        </para>
    </refsection>
    <refsection>
        <title>Examples</title>
        <programlisting role="example"><![CDATA[
            sys = zpk([2;1], [0;-3-%i;-3+%i], 2.5, "c")
            typeof(sys)

            S = zpk2tf(sys)
            typeof(S)

 ]]></programlisting>
        <screen><![CDATA[
        --> sys = zpk([2;1], [0;-3-%i;-3+%i], 2.5, "c")

        sys = [zpk]
       
               (s-2) (s-1)  
          2.5 ------------- 
              s (s^2+6s+10) 
       
       
       --> typeof(sys)
       
        ans = 
       
         "zpk"
       
       --> 
       
       --> S = zpk2tf(sys)
       
        S = [rational] of s
       
          5 -7.5s +2.5s^2  
          ---------------  
          10s +6s^2 +s^3   
       
       --> typeof(S)
       
        ans = 
       
         "rational"
]]></screen>
    </refsection>
    <refsection role="see also">
        <title>See Also</title>
        <simplelist type="inline">
            <member>
                <link linkend="zp2tf">zp2tf</link>
            </member>
            <member>
                <link linkend="zpk2ss">zpk2ss</link>
            </member>
        </simplelist>
    </refsection>
    <refsection role="history">
        <title>History</title>
        <revhistory>
            <revision>
                <revnumber>6.0</revnumber>
                <revdescription>
                    <para>Function added.</para>
                </revdescription>
            </revision>
        </revhistory>
    </refsection>
</refentry>
