<?xml version="1.0" encoding="UTF-8"?>

<!--
 * 
 * This help file was generated from Ctfrker.sci using help_from_sci().
 * 
 -->

<refentry version="5.0-subset Scilab" xml:id="Ctfrker" xml:lang="en"
          xmlns="http://docbook.org/ns/docbook"
          xmlns:xlink="http://www.w3.org/1999/xlink"
          xmlns:svg="http://www.w3.org/2000/svg"
          xmlns:ns3="http://www.w3.org/1999/xhtml"
          xmlns:mml="http://www.w3.org/1998/Math/MathML"
          xmlns:db="http://docbook.org/ns/docbook">

  <info>
    <pubdate>$LastChangedDate: 27-September-2010 $</pubdate>
  </info>

  <refnamediv>
    <refname>Ctfrker</refname><refpurpose>Time frequency representation kernel</refpurpose>
  </refnamediv>



<refsynopsisdiv>
   <title>Calling Sequence</title>
   <synopsis>
   kernel = Ctfrker(N_Doppler,N_Delay,kernel_type)
   kernel = Ctfrker(N_Doppler,N_Delay,kernel_type,optional_parameters)
   </synopsis>
</refsynopsisdiv>

<refsection>
   <title>Parameters</title>
   <variablelist>
   <varlistentry><term>N_doppler   :</term>
      <listitem><para> Number of doppler bins,  number of rows in the kernel matrix</para></listitem></varlistentry>
   <varlistentry><term>N_delay     :</term>
      <listitem><para> Number of delay bins,    number of columns in the kernel matrix</para></listitem></varlistentry>
   <varlistentry><term>kernel      :</term>
      <listitem><para> Computed kernel</para></listitem></varlistentry>
   <varlistentry><term>kernel_type :</term>
      <listitem><para> one of the following types:</para></listitem></varlistentry>
   <varlistentry><term>MTEK    :</term>
      <listitem><para>  Multiform tiltable exponential kernel  7 parameters required :  [alpha beta gamma r tau_0 nu_0 lambda]</para></listitem></varlistentry>
   <varlistentry><term>RGK     :</term>
      <listitem><para> Radially gaussian kernel :   an odd number of parameters required, the  Fourier descriptors of the contour function   [c a1 ... ap b1 ... bp]</para></listitem></varlistentry>
   <varlistentry><term>GMCWK   :</term>
      <listitem><para> Generalized marginals Choi-Williams kernel   at least two parameters required : the kernel width  and the angles of the branches in [0 pi].  [sigma angle_1 .. angle_2]</para></listitem></varlistentry>
   <varlistentry><term>WV      :</term>
      <listitem><para> Wigner-Ville kernel : no parameters required</para></listitem></varlistentry>
   <varlistentry><term>SPECTRO :</term>
      <listitem><para> Spectrogram kernel  The parameters are the window with EVEN length</para></listitem></varlistentry>
   </variablelist>
</refsection>

<refsection>
   <title>Description</title>
   <para>
/ Computes the Cohen's group Time Frequency Representation's (TFR)
kernel, in the ambiguity plane.
   </para>
   <para>
note:  more kernels will be implemented in future versions
</para>
</refsection>

<refsection>
   <title>Examples</title>
   <programlisting role="example"><![CDATA[
AF = Cambifunb(hilbert(sin(2*%pi*0.25*(1:128))),-63:64,128);
ker = Ctfrker(128,128,'rgk',[1 1 1]);
TFR = Caf2tfr(AF,ker);
grayplot(1:128,linspace(0,0.5,128),TFR');

   ]]></programlisting>
</refsection>

<refsection>
   <title>See also</title>
   <simplelist type="inline">
   <member><link linkend="Cambifunb">Cambifunb</link></member>
   <member><link linkend="Caf2tfr">Caf2tfr</link></member>
   </simplelist>
</refsection>
 <refsection>
    <title>Bibliography</title>
    <para>
      H. Costa and G.F. Boudreaux-Bartels, Design of Time-Frequency
      Representations Using a Multiform, Tiltable Exponential Kernel
      IEEE Trans. on Signal Processing, October 1995, vol. 43, no 10,
      pp 2283-2301
    </para>
 <para>
   X.-G. Xia and Y. Owechko and B. H. Soffer and R. M. Matic,
   Generalized-Marginal Time-Frequency Distributions, TFTS 1996,
   pp. 509-51
</para>
  </refsection>
<refsection>
   <title>Authors</title>
   <simplelist type="vert">
   <member>H. Nahrstaedt - Sep 2010</member>
   <member>Emmanuel Roy - 2000</member>
   </simplelist>
</refsection>
</refentry>
