<?xml version="1.0" encoding="UTF-8"?>
<!--
This file is part of the Scilab time frequency toolbox.
This file must be used under the terms of the  terms of the GNU General Public License 
as published by the Free Software Foundation; either version 2 of the License, or
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Copyright (c) 1996 by CNRS (France).
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<refentry xml:id="atoms" 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:scilab="http://www.scilab.org"
          xmlns:ns3="http://www.w3.org/1999/xhtml"
          xmlns:mml="http://www.w3.org/1998/Math/MathML"
          xmlns:db="http://docbook.org/ns/docbook">



  <refnamediv>
    <refname>atoms</refname><refpurpose>Linear combination of elementary Gaussian atoms.</refpurpose>
  </refnamediv>



  <refsynopsisdiv>
    <title>Calling Sequence</title>
    <synopsis>
      [SIG,LOCATOMS] = atoms(N,COORD,DISPLAY)
    </synopsis>
  </refsynopsisdiv>

  <refsection>
    <title>Parameters</title>
    <variablelist>
      <varlistentry>
        <term>	N        :</term>
        <listitem>
          <para> number of points of the signal</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>	COORD    :</term>
        <listitem>
          <para> a real matrix with four columns: the time-frequency
          centers, the ith row has the form [ti,fi,Ti,Ai].</para>
          <para>(ti,fi) are the time-frequency coordinates of atom
          i.</para>
          <para>Ti is its time duration and Ai its amplitude.</para>
          <para>Frequencies f1..fM should be normalized (between 0 and
          0.5).</para>
          <para>If nargin==1, the location of the atoms will be
          defined by clicking with the mouse, with the help of a
          menu. The default value for Ti is N/4.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>SIG:</term>
        <listitem>
          <para>a column complex vector of length N: the output signal.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>LOCATOMS :</term>
        <listitem>
          <para> a real matrix with four columns: matrix of
          time-frequency coordinates and durations of the atoms (see
          COORD).</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsection>

  <refsection>
    <title>Description</title>
    <para>
      atoms generates a signal consisting in a linear combination of elementary
      gaussian wave packets. The locations of the time-frequency centers
      of the different atoms are either fixed by the input parameter COORD
      or successively defined by clicking with the mouse (if NARGIN==1).
    </para>
  </refsection>

  <refsection>
    <title>Examples</title>
    <programlisting role="example"><![CDATA[
    clf;
    coord=[32, 0.3,  32, 1   ;
           56, 0.15, 48, 1.22;
           102,0.41, 20, 0.7 ];
    sig=atoms(128,coord,1);
    ]]></programlisting>
    <scilab:image><![CDATA[
    clf;
    coord=[32, 0.3,  32, 1   ;
           56, 0.15, 48, 1.22;
           102,0.41, 20, 0.7 ];
    sig=atoms(128,coord,1);
    ]]></scilab:image>
  </refsection>

  <refsection>
    <title>Authors</title>
    <simplelist type="vert">
      <member>H. Nahrstaedt - Aug 2010</member>
      <member>	P. Flandrin, May 1995 - O. Lemoine, February 1996.</member>
      <member>	F. Auger - O. Lemoine, June 1996.</member>
      <member>E. Chassande-Mottin, F. Auger, May 1998.</member>
    </simplelist>
  </refsection>
</refentry>
