mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-16 09:45:06 +00:00
122 lines
6.2 KiB
HTML
122 lines
6.2 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- This manual is for FFTW
|
|
(version 3.3.10, 10 December 2020).
|
|
|
|
Copyright (C) 2003 Matteo Frigo.
|
|
|
|
Copyright (C) 2003 Massachusetts Institute of Technology.
|
|
|
|
Permission is granted to make and distribute verbatim copies of this
|
|
manual provided the copyright notice and this permission notice are
|
|
preserved on all copies.
|
|
|
|
Permission is granted to copy and distribute modified versions of this
|
|
manual under the conditions for verbatim copying, provided that the
|
|
entire resulting derived work is distributed under the terms of a
|
|
permission notice identical to this one.
|
|
|
|
Permission is granted to copy and distribute translations of this manual
|
|
into another language, under the above conditions for modified versions,
|
|
except that this permission notice may be stated in a translation
|
|
approved by the Free Software Foundation. -->
|
|
<!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<title>Advanced Real-data DFTs (FFTW 3.3.10)</title>
|
|
|
|
<meta name="description" content="Advanced Real-data DFTs (FFTW 3.3.10)">
|
|
<meta name="keywords" content="Advanced Real-data DFTs (FFTW 3.3.10)">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<link href="index.html" rel="start" title="Top">
|
|
<link href="Concept-Index.html" rel="index" title="Concept Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="Advanced-Interface.html" rel="up" title="Advanced Interface">
|
|
<link href="Advanced-Real_002dto_002dreal-Transforms.html" rel="next" title="Advanced Real-to-real Transforms">
|
|
<link href="Advanced-Complex-DFTs.html" rel="prev" title="Advanced Complex DFTs">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
kbd {font-style: oblique}
|
|
pre.display {font-family: inherit}
|
|
pre.format {font-family: inherit}
|
|
pre.menu-comment {font-family: serif}
|
|
pre.menu-preformatted {font-family: serif}
|
|
span.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<span id="Advanced-Real_002ddata-DFTs"></span><div class="header">
|
|
<p>
|
|
Next: <a href="Advanced-Real_002dto_002dreal-Transforms.html" accesskey="n" rel="next">Advanced Real-to-real Transforms</a>, Previous: <a href="Advanced-Complex-DFTs.html" accesskey="p" rel="prev">Advanced Complex DFTs</a>, Up: <a href="Advanced-Interface.html" accesskey="u" rel="up">Advanced Interface</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
<hr>
|
|
<span id="Advanced-Real_002ddata-DFTs-1"></span><h4 class="subsection">4.4.2 Advanced Real-data DFTs</h4>
|
|
|
|
<div class="example">
|
|
<pre class="example">fftw_plan fftw_plan_many_dft_r2c(int rank, const int *n, int howmany,
|
|
double *in, const int *inembed,
|
|
int istride, int idist,
|
|
fftw_complex *out, const int *onembed,
|
|
int ostride, int odist,
|
|
unsigned flags);
|
|
fftw_plan fftw_plan_many_dft_c2r(int rank, const int *n, int howmany,
|
|
fftw_complex *in, const int *inembed,
|
|
int istride, int idist,
|
|
double *out, const int *onembed,
|
|
int ostride, int odist,
|
|
unsigned flags);
|
|
</pre></div>
|
|
<span id="index-fftw_005fplan_005fmany_005fdft_005fr2c"></span>
|
|
<span id="index-fftw_005fplan_005fmany_005fdft_005fc2r"></span>
|
|
|
|
<p>Like <code>fftw_plan_many_dft</code>, these two functions add <code>howmany</code>,
|
|
<code>nembed</code>, <code>stride</code>, and <code>dist</code> parameters to the
|
|
<code>fftw_plan_dft_r2c</code> and <code>fftw_plan_dft_c2r</code> functions, but
|
|
otherwise behave the same as the basic interface.
|
|
</p>
|
|
<p>The interpretation of <code>howmany</code>, <code>stride</code>, and <code>dist</code> are
|
|
the same as for <code>fftw_plan_many_dft</code>, above. Note that the
|
|
<code>stride</code> and <code>dist</code> for the real array are in units of
|
|
<code>double</code>, and for the complex array are in units of
|
|
<code>fftw_complex</code>.
|
|
</p>
|
|
<p>If an <code>nembed</code> parameter is <code>NULL</code>, it is interpreted as what
|
|
it would be in the basic interface, as described in <a href="Real_002ddata-DFT-Array-Format.html">Real-data DFT Array Format</a>. That is, for the complex array the size is assumed to be
|
|
the same as <code>n</code>, but with the last dimension cut roughly in half.
|
|
For the real array, the size is assumed to be <code>n</code> if the transform
|
|
is out-of-place, or <code>n</code> with the last dimension “padded” if the
|
|
transform is in-place.
|
|
</p>
|
|
<p>If an <code>nembed</code> parameter is non-<code>NULL</code>, it is interpreted as
|
|
the physical size of the corresponding array, in row-major order, just
|
|
as for <code>fftw_plan_many_dft</code>. In this case, each dimension of
|
|
<code>nembed</code> should be <code>>=</code> what it would be in the basic
|
|
interface (e.g. the halved or padded <code>n</code>).
|
|
</p>
|
|
<p>Arrays <code>n</code>, <code>inembed</code>, and <code>onembed</code> are not used after
|
|
this function returns. You can safely free or reuse them.
|
|
</p>
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Advanced-Real_002dto_002dreal-Transforms.html" accesskey="n" rel="next">Advanced Real-to-real Transforms</a>, Previous: <a href="Advanced-Complex-DFTs.html" accesskey="p" rel="prev">Advanced Complex DFTs</a>, Up: <a href="Advanced-Interface.html" accesskey="u" rel="up">Advanced Interface</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|