96 lines
4 KiB
HTML
96 lines
4 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>Interleaved and split arrays (FFTW 3.3.10)</title>
|
|
|
|
<meta name="description" content="Interleaved and split arrays (FFTW 3.3.10)">
|
|
<meta name="keywords" content="Interleaved and split arrays (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="Guru-Interface.html" rel="up" title="Guru Interface">
|
|
<link href="Guru-vector-and-transform-sizes.html" rel="next" title="Guru vector and transform sizes">
|
|
<link href="Guru-Interface.html" rel="prev" title="Guru Interface">
|
|
<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="Interleaved-and-split-arrays"></span><div class="header">
|
|
<p>
|
|
Next: <a href="Guru-vector-and-transform-sizes.html" accesskey="n" rel="next">Guru vector and transform sizes</a>, Previous: <a href="Guru-Interface.html" accesskey="p" rel="prev">Guru Interface</a>, Up: <a href="Guru-Interface.html" accesskey="u" rel="up">Guru 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="Interleaved-and-split-arrays-1"></span><h4 class="subsection">4.5.1 Interleaved and split arrays</h4>
|
|
|
|
<p>The guru interface supports two representations of complex numbers,
|
|
which we call the interleaved and the split format.
|
|
</p>
|
|
<p>The <em>interleaved</em> format is the same one used by the basic and
|
|
advanced interfaces, and it is documented in <a href="Complex-numbers.html">Complex numbers</a>.
|
|
In the interleaved format, you provide pointers to the real part of a
|
|
complex number, and the imaginary part understood to be stored in the
|
|
next memory location.
|
|
<span id="index-interleaved-format"></span>
|
|
</p>
|
|
|
|
<p>The <em>split</em> format allows separate pointers to the real and
|
|
imaginary parts of a complex array.
|
|
<span id="index-split-format"></span>
|
|
</p>
|
|
|
|
<p>Technically, the interleaved format is redundant, because you can
|
|
always express an interleaved array in terms of a split array with
|
|
appropriate pointers and strides. On the other hand, the interleaved
|
|
format is simpler to use, and it is common in practice. Hence, FFTW
|
|
supports it as a special case.
|
|
</p>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|