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<refentry version="5.0-subset Scilab" xml:id="Ctfrbud" xml:lang="en"
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  <refnamediv>
    <refname>Ctfrbud</refname>
	<refpurpose>Butterworth time-frequency distribution</refpurpose>
  </refnamediv>

<refsynopsisdiv>
   <title>Calling Sequence</title>
   <synopsis>
   [TFR,T,F] = Ctfrbud(X)
   [TFR,T,F] = Ctfrbud(X, T)
   [TFR,T,F] = Ctfrbud(X, T, N)
   [TFR,T,F] = Ctfrbud(X, T, N, G)
   [TFR,T,F] = Ctfrbud(X, T, N, G, H)
   [TFR,T,F] = Ctfrbud(X, T, N, G, H, SIGMA)
   </synopsis>
</refsynopsisdiv>

<refsection>
   <title>Parameters</title>
   <variablelist>
   <varlistentry><term>X     :</term>
      <listitem><para> Analyzed signal</para></listitem></varlistentry>
   <varlistentry><term>T     :</term>
      <listitem><para> time instant(s)          (default : 1:length(X)).</para></listitem></varlistentry>
   <varlistentry><term>N     :</term>
      <listitem><para> number of frequency bins (default : length(X)).</para></listitem></varlistentry>
   <varlistentry><term>G     :</term>
      <listitem><para> time smoothing window    (default : Hamming(N/4)).</para></listitem></varlistentry>
   <varlistentry><term>H     :</term>
      <listitem><para> frequency smoothing window(default : Hamming(N/4)).</para></listitem></varlistentry>
   <varlistentry><term>SIGMA :</term>
      <listitem><para> kernel width             (default : 1).</para></listitem></varlistentry>
   <varlistentry><term>TFR   :</term>
      <listitem><para> time-frequency representation</para></listitem></varlistentry>
   <varlistentry><term>F     :</term>
      <listitem><para> vector of normalized frequencies.</para></listitem></varlistentry>
   </variablelist>
</refsection>

<refsection>
   <title>Description</title>
   <para>
computes the Butterworth distribution of a signal X.
</para>
</refsection>

<refsection>
   <title>Examples</title>
   <programlisting role="example"><![CDATA[
x = hilbert(sin(2*%pi*0.25*(1:128))+0.5*rand(1,128,'normal'));
g = Cwindow(9,'Hamming');
h = Cwindow(27,'Hamming');
t = 1:128;
[tfr,T,F] = Ctfrbud(x,t,128,g,h,3.6);
grayplot(T,F,tfr');
xlabel time
ylabel frequency
   ]]></programlisting>
</refsection>

<refsection>
   <title>Authors</title>
   <simplelist type="vert">
   <member>H. Nahrstaedt - Sep 2010</member>
   <member>Emmanuel Roy - 2000</member>
   <member>Manuel Davy - 2000</member>
   </simplelist>
</refsection>
</refentry>
