blob: 0912bc104e47c30aad100b8308faefe4c289d8c6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>ifft</title>
<style type="text/css" media="all">
@import url("scilab_code.css");
@import url("xml_code.css");
@import url("c_code.css");
@import url("style.css");
</style>
</head>
<body>
<div class="manualnavbar">
<table width="100%"><tr>
<td width="30%">
<span class="previous"><a href="idst1.html"><< idst1</a></span>
</td>
<td width="40%" class="center">
<span class="top"><a href="section_cc2bc01c47967d47fcf3507a91d572ba.html">FOSSEE Signal Processing Toolbox</a></span>
</td>
<td width="30%" class="next">
<span class="next"><a href="ifft1.html">ifft1 >></a></span>
</td>
</tr></table>
<hr />
</div>
<span class="path"><a href="index.html">FOSSEE Signal Processing Toolbox</a> >> <a href="section_cc2bc01c47967d47fcf3507a91d572ba.html">FOSSEE Signal Processing Toolbox</a> > ifft</span>
<br /><br />
<div class="refnamediv"><h1 class="refname">ifft</h1>
<p class="refpurpose">Calculates the inverse discrete Fourier transform of a matrix using Fast Fourier Transform algorithm.</p></div>
<div class="refsynopsisdiv"><h3 class="title">Calling Sequence</h3>
<div class="synopsis"><pre><span class="functionid">ifft</span><span class="default"> (</span><span class="default">x</span><span class="default">, </span><span class="default">n</span><span class="default">, </span><span class="default">dim</span><span class="default">)</span>
<span class="functionid">ifft</span><span class="default"> (</span><span class="default">x</span><span class="default">, </span><span class="default">n</span><span class="default">)</span>
<span class="functionid">ifft</span><span class="default"> (</span><span class="default">x</span><span class="default">)</span></pre></div></div>
<div class="refsection"><h3 class="title">Parameters</h3>
<dl><dt><span class="term">x:</span>
<dd><p class="para">input matrix</p></dd></dt>
<dt><span class="term">n:</span>
<dd><p class="para">Specifies the number of elements of x to be used</p></dd></dt>
<dt><span class="term">dim:</span>
<dd><p class="para">Specifies the dimention of the matrix along which the inverse FFT is performed</p></dd></dt></dl></div>
<div class="refsection"><h3 class="title">Description</h3>
<p class="para">This is an Octave function.</p></div>
<div class="refsection"><h3 class="title">Description</h3>
<p class="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.</p>
<p class="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.</p>
<p class="para">dim is an integer specifying the dimension of the matrix along which the inverse FFT is performed.</p></div>
<div class="refsection"><h3 class="title">Examples</h3>
<div class="programlisting"><table border="0" width="100%"><tr><td width="98%"><pre class="scilabcode"><span class="scilabid">x</span> <span class="scilaboperator">=</span> <span class="scilabopenclose">[</span><span class="scilabnumber">1</span> <span class="scilabnumber">2</span> <span class="scilabnumber">3</span><span class="scilabdefault">;</span> <span class="scilabnumber">4</span> <span class="scilabnumber">5</span> <span class="scilabnumber">6</span><span class="scilabdefault">;</span> <span class="scilabnumber">7</span> <span class="scilabnumber">8</span> <span class="scilabnumber">9</span><span class="scilabopenclose">]</span>
<span class="scilabid">n</span> <span class="scilaboperator">=</span> <span class="scilabnumber">3</span>
<span class="scilabid">dim</span> <span class="scilaboperator">=</span> <span class="scilabnumber">2</span>
<span class="scilabmacro">ifft</span> <span class="scilabopenclose">(</span><span class="scilabid">x</span><span class="scilabdefault">,</span> <span class="scilabid">n</span><span class="scilabdefault">,</span> <span class="scilabid">dim</span><span class="scilabopenclose">)</span>
<span class="scilabid">ans</span> <span class="scilaboperator">=</span>
<span class="scilabnumber">2.00000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.00000</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">-</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span>
<span class="scilabnumber">5.00000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.00000</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">-</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span>
<span class="scilabnumber">8.00000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.00000</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">-</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span> <span class="scilaboperator">-</span><span class="scilabnumber">0.50000</span> <span class="scilaboperator">+</span> <span class="scilabnumber">0.28868</span><span class="scilabid">i</span></pre></td><td valign="top"><a href="scilab://scilab.execexample/"><img src="ScilabExecute.png" border="0"/></a></td><td valign="top"><a href="scilab://scilab.editexample/"><img src="ScilabEdit.png" border="0"/></a></td><td></td></tr></table></div></div>
<br />
<div class="manualnavbar">
<table width="100%">
<tr><td colspan="3" class="next"><a href="http://bugzilla.scilab.org/enter_bug.cgi?product=Scilab%20software&component=Documentation%20pages" class="ulink">Report an issue</a></td></tr>
<tr>
<td width="30%">
<span class="previous"><a href="idst1.html"><< idst1</a></span>
</td>
<td width="40%" class="center">
<span class="top"><a href="section_cc2bc01c47967d47fcf3507a91d572ba.html">FOSSEE Signal Processing Toolbox</a></span>
</td>
<td width="30%" class="next">
<span class="next"><a href="ifft1.html">ifft1 >></a></span>
</td>
</tr></table>
<hr />
</div>
</body>
</html>
|
