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Update Vamp plugin SDK to 2.5
author Chris Cannam
date Thu, 09 May 2013 10:52:46 +0100
parents 37bf6b4a2645
children
rev   line source
Chris@10 1 <html lang="en">
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Chris@10 3 <title>Precision - FFTW 3.3.3</title>
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Chris@10 12 <!--
Chris@10 13 This manual is for FFTW
Chris@10 14 (version 3.3.3, 25 November 2012).
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Chris@10 16 Copyright (C) 2003 Matteo Frigo.
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Chris@10 48 <div class="node">
Chris@10 49 <a name="Precision"></a>
Chris@10 50 <p>
Chris@10 51 Next:&nbsp;<a rel="next" accesskey="n" href="Memory-Allocation.html#Memory-Allocation">Memory Allocation</a>,
Chris@10 52 Previous:&nbsp;<a rel="previous" accesskey="p" href="Complex-numbers.html#Complex-numbers">Complex numbers</a>,
Chris@10 53 Up:&nbsp;<a rel="up" accesskey="u" href="Data-Types-and-Files.html#Data-Types-and-Files">Data Types and Files</a>
Chris@10 54 <hr>
Chris@10 55 </div>
Chris@10 56
Chris@10 57 <h4 class="subsection">4.1.2 Precision</h4>
Chris@10 58
Chris@10 59 <p><a name="index-precision-143"></a>
Chris@10 60 You can install single and long-double precision versions of FFTW,
Chris@10 61 which replace <code>double</code> with <code>float</code> and <code>long double</code>,
Chris@10 62 respectively (see <a href="Installation-and-Customization.html#Installation-and-Customization">Installation and Customization</a>). To use these
Chris@10 63 interfaces, you:
Chris@10 64
Chris@10 65 <ul>
Chris@10 66 <li>Link to the single/long-double libraries; on Unix, <code>-lfftw3f</code> or
Chris@10 67 <code>-lfftw3l</code> instead of (or in addition to) <code>-lfftw3</code>. (You
Chris@10 68 can link to the different-precision libraries simultaneously.)
Chris@10 69
Chris@10 70 <li>Include the <em>same</em> <code>&lt;fftw3.h&gt;</code> header file.
Chris@10 71
Chris@10 72 <li>Replace all lowercase instances of &lsquo;<samp><span class="samp">fftw_</span></samp>&rsquo; with &lsquo;<samp><span class="samp">fftwf_</span></samp>&rsquo; or
Chris@10 73 &lsquo;<samp><span class="samp">fftwl_</span></samp>&rsquo; for single or long-double precision, respectively.
Chris@10 74 (<code>fftw_complex</code> becomes <code>fftwf_complex</code>, <code>fftw_execute</code>
Chris@10 75 becomes <code>fftwf_execute</code>, etcetera.)
Chris@10 76
Chris@10 77 <li>Uppercase names, i.e. names beginning with &lsquo;<samp><span class="samp">FFTW_</span></samp>&rsquo;, remain the
Chris@10 78 same.
Chris@10 79
Chris@10 80 <li>Replace <code>double</code> with <code>float</code> or <code>long double</code> for
Chris@10 81 subroutine parameters.
Chris@10 82
Chris@10 83 </ul>
Chris@10 84
Chris@10 85 <p>Depending upon your compiler and/or hardware, <code>long double</code> may not
Chris@10 86 be any more precise than <code>double</code> (or may not be supported at all,
Chris@10 87 although it is standard in C99).
Chris@10 88 <a name="index-C99-144"></a>
Chris@10 89
Chris@10 90 <p>We also support using the nonstandard <code>__float128</code>
Chris@10 91 quadruple-precision type provided by recent versions of <code>gcc</code> on
Chris@10 92 32- and 64-bit x86 hardware (see <a href="Installation-and-Customization.html#Installation-and-Customization">Installation and Customization</a>).
Chris@10 93 To use this type, link with <code>-lfftw3q -lquadmath -lm</code> (the
Chris@10 94 <code>libquadmath</code> library provided by <code>gcc</code> is needed for
Chris@10 95 quadruple-precision trigonometric functions) and use &lsquo;<samp><span class="samp">fftwq_</span></samp>&rsquo;
Chris@10 96 identifiers.
Chris@10 97
Chris@10 98 <!-- =========> -->
Chris@10 99 </body></html>
Chris@10 100