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

<!--
 *
 * This help file was generated from ifft1.sci using help_from_sci().
 *
 -->

<refentry version="5.0-subset Scilab" xml:id="ifft1" 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:scilab="http://www.scilab.org"
          xmlns:db="http://docbook.org/ns/docbook">

  <refnamediv>
    <refname>ifft1</refname>
    <refpurpose>Calculates the inverse discrete Fourier transform of a matrix using Fast Fourier Transform algorithm.</refpurpose>
  </refnamediv>


<refsynopsisdiv>
   <title>Calling Sequence</title>
   <synopsis>
   ifft (x, n, dim)
   ifft (x, n)
   ifft (x)
   </synopsis>
</refsynopsisdiv>

<refsection>
   <title>Parameters</title>
   <variablelist>
   <varlistentry><term>x:</term>
      <listitem><para> input matrix</para></listitem></varlistentry>
   <varlistentry><term>n:</term>
      <listitem><para> Specifies the number of elements of x to be used</para></listitem></varlistentry>
   <varlistentry><term>dim:</term>
      <listitem><para> Specifies the dimention of the matrix along which the inverse FFT is performed</para></listitem></varlistentry>
   </variablelist>
</refsection>

<refsection>
   <title>Description</title>
   <para>
This is an Octave function.
</para>
</refsection>

<refsection>
   <title>Description</title>
   <para>
This is an Octave function.
The inverse FFT is calculated along the first non-singleton dimension of the array. Thus, inverse FFT is computed for each column of x.
   </para>
   <para>
n is an integer specifying the number of elements of x to use. If n is larger than dimention along. which the inverse FFT is calculated, then x is resized and padded with zeros.
Similarly, if n is smaller, then x is truncated.
   </para>
   <para>
dim is an integer specifying the dimension of the matrix along which the inverse FFT is performed.
</para>
</refsection>

<refsection>
   <title>Examples</title>
   <programlisting role="example"><![CDATA[
x = [1 2 3; 4 5 6; 7 8 9]
n = 3
dim = 2
ifft1 (x, n, dim)
ans =

2.00000 + 0.00000i  -0.50000 - 0.28868i  -0.50000 + 0.28868i
5.00000 + 0.00000i  -0.50000 - 0.28868i  -0.50000 + 0.28868i
8.00000 + 0.00000i  -0.50000 - 0.28868i  -0.50000 + 0.28868i
   ]]></programlisting>
</refsection>
</refentry>