Mercurial > hg > sv-dependency-builds
diff src/fftw-3.3.3/doc/html/Precision.html @ 95:89f5e221ed7b
Add FFTW3
| author | Chris Cannam <cannam@all-day-breakfast.com> |
|---|---|
| date | Wed, 20 Mar 2013 15:35:50 +0000 |
| parents | |
| children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/fftw-3.3.3/doc/html/Precision.html Wed Mar 20 15:35:50 2013 +0000 @@ -0,0 +1,100 @@ +<html lang="en"> +<head> +<title>Precision - FFTW 3.3.3</title> +<meta http-equiv="Content-Type" content="text/html"> +<meta name="description" content="FFTW 3.3.3"> +<meta name="generator" content="makeinfo 4.13"> +<link title="Top" rel="start" href="index.html#Top"> +<link rel="up" href="Data-Types-and-Files.html#Data-Types-and-Files" title="Data Types and Files"> +<link rel="prev" href="Complex-numbers.html#Complex-numbers" title="Complex numbers"> +<link rel="next" href="Memory-Allocation.html#Memory-Allocation" title="Memory Allocation"> +<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> +<!-- +This manual is for FFTW +(version 3.3.3, 25 November 2012). + +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. + --> +<meta http-equiv="Content-Style-Type" content="text/css"> +<style type="text/css"><!-- + pre.display { font-family:inherit } + pre.format { font-family:inherit } + pre.smalldisplay { font-family:inherit; font-size:smaller } + pre.smallformat { font-family:inherit; font-size:smaller } + pre.smallexample { font-size:smaller } + pre.smalllisp { font-size:smaller } + span.sc { font-variant:small-caps } + span.roman { font-family:serif; font-weight:normal; } + span.sansserif { font-family:sans-serif; font-weight:normal; } +--></style> +</head> +<body> +<div class="node"> +<a name="Precision"></a> +<p> +Next: <a rel="next" accesskey="n" href="Memory-Allocation.html#Memory-Allocation">Memory Allocation</a>, +Previous: <a rel="previous" accesskey="p" href="Complex-numbers.html#Complex-numbers">Complex numbers</a>, +Up: <a rel="up" accesskey="u" href="Data-Types-and-Files.html#Data-Types-and-Files">Data Types and Files</a> +<hr> +</div> + +<h4 class="subsection">4.1.2 Precision</h4> + +<p><a name="index-precision-143"></a> +You can install single and long-double precision versions of FFTW, +which replace <code>double</code> with <code>float</code> and <code>long double</code>, +respectively (see <a href="Installation-and-Customization.html#Installation-and-Customization">Installation and Customization</a>). To use these +interfaces, you: + + <ul> +<li>Link to the single/long-double libraries; on Unix, <code>-lfftw3f</code> or +<code>-lfftw3l</code> instead of (or in addition to) <code>-lfftw3</code>. (You +can link to the different-precision libraries simultaneously.) + + <li>Include the <em>same</em> <code><fftw3.h></code> header file. + + <li>Replace all lowercase instances of ‘<samp><span class="samp">fftw_</span></samp>’ with ‘<samp><span class="samp">fftwf_</span></samp>’ or +‘<samp><span class="samp">fftwl_</span></samp>’ for single or long-double precision, respectively. +(<code>fftw_complex</code> becomes <code>fftwf_complex</code>, <code>fftw_execute</code> +becomes <code>fftwf_execute</code>, etcetera.) + + <li>Uppercase names, i.e. names beginning with ‘<samp><span class="samp">FFTW_</span></samp>’, remain the +same. + + <li>Replace <code>double</code> with <code>float</code> or <code>long double</code> for +subroutine parameters. + + </ul> + + <p>Depending upon your compiler and/or hardware, <code>long double</code> may not +be any more precise than <code>double</code> (or may not be supported at all, +although it is standard in C99). +<a name="index-C99-144"></a> + + <p>We also support using the nonstandard <code>__float128</code> +quadruple-precision type provided by recent versions of <code>gcc</code> on +32- and 64-bit x86 hardware (see <a href="Installation-and-Customization.html#Installation-and-Customization">Installation and Customization</a>). +To use this type, link with <code>-lfftw3q -lquadmath -lm</code> (the +<code>libquadmath</code> library provided by <code>gcc</code> is needed for +quadruple-precision trigonometric functions) and use ‘<samp><span class="samp">fftwq_</span></samp>’ +identifiers. + +<!-- =========> --> + </body></html> +