scilab/modules/cacsd/help/en_US/linear_analysis/freq_domain/freson.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
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  16 <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="freson">
  17     <refnamediv>
  18         <refname>freson</refname>
  19         <refpurpose>peak frequencies</refpurpose>
  20     </refnamediv>
  21     <refsynopsisdiv>
  22         <title>Syntax</title>
  23         <synopsis>fr=freson(h)</synopsis>
  24     </refsynopsisdiv>
  25     <refsection>
  26         <title>Arguments</title>
  27         <variablelist>
  28             <varlistentry>
  29                 <term>h</term>
  30                 <listitem>
  31                     <para>
  32                         A siso linear dynamical system, in state space, transfer function or zpk representations.
  33                     </para>
  34                 </listitem>
  35             </varlistentry>
  36             <varlistentry>
  37                 <term>fr</term>
  38                 <listitem>
  39                     <para>vector of peak frequencies in Hz</para>
  40                 </listitem>
  41             </varlistentry>
  42         </variablelist>
  43     </refsection>
  44     <refsection>
  45         <title>Description</title>
  46         <para>
  47             returns the vector frequencies at which the response
  48             amplitude of a siso dynamical system is a relative maximum
  49             also called resonance frequencies.
  50
  51         </para>
  52     </refsection>
  53     <refsection>
  54         <title>Examples</title>
  55         <para>Continuous time system</para>
  56         <programlisting role="example"><![CDATA[
  57 h=syslin('c',-1+%s,(3+2*%s+%s^2)*(50+0.1*%s+%s^2));
  58 fr=freson(h)
  59 clf;bode(h);
  60 fig=gcf();sca(fig.children(2));
  61 [phi,db]=phasemag(repfreq(h,fr));
  62 plot(fr,db(:),'+r')
  63 ]]></programlisting>
  64         <scilab:image>
  65             h=syslin('c',-1+%s,(3+2*%s+%s^2)*(50+0.1*%s+%s^2));
  66             fr=freson(h)
  67             clf;bode(h);
  68             fig=gcf();sca(fig.children(2));
  69             [phi,db]=phasemag(repfreq(h,fr));
  70             plot(fr,db(:),'+r');
  71         </scilab:image>
  72         <para>Discrete time system</para>
  73         <programlisting role="example"><![CDATA[
  74 hd=dscr(h,0.01)
  75 fr=freson(hd)
  76 clf;bode(hd);
  77 fig=gcf();sca(fig.children(2));
  78 [phi,db]=phasemag(repfreq(hd,fr));
  79 plot(fr,db(:),'+r');
  80
  81  ]]></programlisting>
  82         <scilab:image>
  83             h=syslin('c',-1+%s,(3+2*%s+%s^2)*(50+0.1*%s+%s^2));
  84             hd=dscr(h,0.05);
  85             fr=freson(hd);
  86             clf;bode(hd);
  87             fig=gcf();sca(fig.children(2));
  88             [phi,db]=phasemag(repfreq(hd,fr));
  89             plot(fr,db(:),'+r');
  90         </scilab:image>
  91     </refsection>
  92     <refsection role="see also">
  93         <title>See also</title>
  94         <simplelist type="inline">
  95             <member>
  96                 <link linkend="frep2tf">frep2tf</link>
  97             </member>
  98             <member>
  99                 <link linkend="zgrid">zgrid</link>
 100             </member>
 101             <member>
 102                 <link linkend="h_norm">h_norm</link>
 103             </member>
 104         </simplelist>
 105     </refsection>
 106     <refsection role="history">
 107         <title>History</title>
 108         <revhistory>
 109             <revision>
 110                 <revnumber>6.0</revnumber>
 111                 <revdescription>
 112                     <para>handling discrete systems and zpk
 113                         representation, peak detection improved.
 114                     </para>
 115                 </revdescription>
 116             </revision>
 117         </revhistory>
 118     </refsection>
 119 </refentry>