Mercurial > hg > batch-feature-extraction-tool
diff Lib/fftw-3.2.1/doc/html/.svn/text-base/New_002darray-Execute-Functions.html.svn-base @ 15:585caf503ef5 tip
Tidy up for ROLI
| author | Geogaddi\David <d.m.ronan@qmul.ac.uk> |
|---|---|
| date | Tue, 17 May 2016 18:50:19 +0100 |
| parents | 636c989477e7 |
| children |
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--- a/Lib/fftw-3.2.1/doc/html/.svn/text-base/New_002darray-Execute-Functions.html.svn-base Wed May 04 11:02:59 2016 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,152 +0,0 @@ -<html lang="en"> -<head> -<title>New-array Execute Functions - FFTW 3.2.1</title> -<meta http-equiv="Content-Type" content="text/html"> -<meta name="description" content="FFTW 3.2.1"> -<meta name="generator" content="makeinfo 4.8"> -<link title="Top" rel="start" href="index.html#Top"> -<link rel="up" href="FFTW-Reference.html#FFTW-Reference" title="FFTW Reference"> -<link rel="prev" href="Guru-Interface.html#Guru-Interface" title="Guru Interface"> -<link rel="next" href="Wisdom.html#Wisdom" title="Wisdom"> -<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> -<!-- -This manual is for FFTW -(version 3.2.1, 5 February 2009). - -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"> -<p> -<a name="New-array-Execute-Functions"></a> -<a name="New_002darray-Execute-Functions"></a> -Next: <a rel="next" accesskey="n" href="Wisdom.html#Wisdom">Wisdom</a>, -Previous: <a rel="previous" accesskey="p" href="Guru-Interface.html#Guru-Interface">Guru Interface</a>, -Up: <a rel="up" accesskey="u" href="FFTW-Reference.html#FFTW-Reference">FFTW Reference</a> -<hr> -</div> - -<h3 class="section">4.6 New-array Execute Functions</h3> - -<p><a name="index-execute-256"></a><a name="index-new_002darray-execution-257"></a> -Normally, one executes a plan for the arrays with which the plan was -created, by calling <code>fftw_execute(plan)</code> as described in <a href="Using-Plans.html#Using-Plans">Using Plans</a>. -<a name="index-fftw_005fexecute-258"></a>However, it is possible for sophisticated users to apply a given plan -to a <em>different</em> array using the “new-array execute” functions -detailed below, provided that the following conditions are met: - - <ul> -<li>The array size, strides, etcetera are the same (since those are set by -the plan). - - <li>The input and output arrays are the same (in-place) or different -(out-of-place) if the plan was originally created to be in-place or -out-of-place, respectively. - - <li>For split arrays, the separations between the real and imaginary -parts, <code>ii-ri</code> and <code>io-ro</code>, are the same as they were for -the input and output arrays when the plan was created. (This -condition is automatically satisfied for interleaved arrays.) - - <li>The <dfn>alignment</dfn> of the new input/output arrays is the same as that -of the input/output arrays when the plan was created, unless the plan -was created with the <code>FFTW_UNALIGNED</code> flag. -<a name="index-FFTW_005fUNALIGNED-259"></a>Here, the alignment is a platform-dependent quantity (for example, it is -the address modulo 16 if SSE SIMD instructions are used, but the address -modulo 4 for non-SIMD single-precision FFTW on the same machine). In -general, only arrays allocated with <code>fftw_malloc</code> are guaranteed to -be equally aligned (see <a href="SIMD-alignment-and-fftw_005fmalloc.html#SIMD-alignment-and-fftw_005fmalloc">SIMD alignment and fftw_malloc</a>). - - </ul> - - <p><a name="index-alignment-260"></a>The alignment issue is especially critical, because if you don't use -<code>fftw_malloc</code> then you may have little control over the alignment -of arrays in memory. For example, neither the C++ <code>new</code> function -nor the Fortran <code>allocate</code> statement provide strong enough -guarantees about data alignment. If you don't use <code>fftw_malloc</code>, -therefore, you probably have to use <code>FFTW_UNALIGNED</code> (which -disables most SIMD support). If possible, it is probably better for -you to simply create multiple plans (creating a new plan is quick once -one exists for a given size), or better yet re-use the same array for -your transforms. - - <p>If you are tempted to use the new-array execute interface because you -want to transform a known bunch of arrays of the same size, you should -probably go use the advanced interface instead (see <a href="Advanced-Interface.html#Advanced-Interface">Advanced Interface</a>)). - - <p>The new-array execute functions are: - -<pre class="example"> void fftw_execute_dft( - const fftw_plan p, - fftw_complex *in, fftw_complex *out); - - void fftw_execute_split_dft( - const fftw_plan p, - double *ri, double *ii, double *ro, double *io); - - void fftw_execute_dft_r2c( - const fftw_plan p, - double *in, fftw_complex *out); - - void fftw_execute_split_dft_r2c( - const fftw_plan p, - double *in, double *ro, double *io); - - void fftw_execute_dft_c2r( - const fftw_plan p, - fftw_complex *in, double *out); - - void fftw_execute_split_dft_c2r( - const fftw_plan p, - double *ri, double *ii, double *out); - - void fftw_execute_r2r( - const fftw_plan p, - double *in, double *out); -</pre> - <p><a name="index-fftw_005fexecute_005fdft-261"></a><a name="index-fftw_005fexecute_005fsplit_005fdft-262"></a><a name="index-fftw_005fexecute_005fdft_005fr2c-263"></a><a name="index-fftw_005fexecute_005fsplit_005fdft_005fr2c-264"></a><a name="index-fftw_005fexecute_005fdft_005fc2r-265"></a><a name="index-fftw_005fexecute_005fsplit_005fdft_005fc2r-266"></a><a name="index-fftw_005fexecute_005fdft_005fr2r-267"></a> -These execute the <code>plan</code> to compute the corresponding transform on -the input/output arrays specified by the subsequent arguments. The -input/output array arguments have the same meanings as the ones passed -to the guru planner routines in the preceding sections. The <code>plan</code> -is not modified, and these routines can be called as many times as -desired, or intermixed with calls to the ordinary <code>fftw_execute</code>. - - <p>The <code>plan</code> <em>must</em> have been created for the transform type -corresponding to the execute function, e.g. it must be a complex-DFT -plan for <code>fftw_execute_dft</code>. Any of the planner routines for that -transform type, from the basic to the guru interface, could have been -used to create the plan, however. - -<!-- --> -</body></html> -