Mercurial > hg > batch-feature-extraction-tool
diff Lib/fftw-3.2.1/doc/html/.svn/text-base/Dynamic-Arrays-in-C.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/Dynamic-Arrays-in-C.html.svn-base Wed May 04 11:02:59 2016 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,91 +0,0 @@ -<html lang="en"> -<head> -<title>Dynamic Arrays in C - 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="Multi_002ddimensional-Array-Format.html#Multi_002ddimensional-Array-Format" title="Multi-dimensional Array Format"> -<link rel="prev" href="Fixed_002dsize-Arrays-in-C.html#Fixed_002dsize-Arrays-in-C" title="Fixed-size Arrays in C"> -<link rel="next" href="Dynamic-Arrays-in-C_002dThe-Wrong-Way.html#Dynamic-Arrays-in-C_002dThe-Wrong-Way" title="Dynamic Arrays in C-The Wrong Way"> -<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="Dynamic-Arrays-in-C"></a> -Next: <a rel="next" accesskey="n" href="Dynamic-Arrays-in-C_002dThe-Wrong-Way.html#Dynamic-Arrays-in-C_002dThe-Wrong-Way">Dynamic Arrays in C-The Wrong Way</a>, -Previous: <a rel="previous" accesskey="p" href="Fixed_002dsize-Arrays-in-C.html#Fixed_002dsize-Arrays-in-C">Fixed-size Arrays in C</a>, -Up: <a rel="up" accesskey="u" href="Multi_002ddimensional-Array-Format.html#Multi_002ddimensional-Array-Format">Multi-dimensional Array Format</a> -<hr> -</div> - -<h4 class="subsection">3.2.4 Dynamic Arrays in C</h4> - -<p>We recommend allocating most arrays dynamically, with -<code>fftw_malloc</code>. This isn't too hard to do, although it is not as -straightforward for multi-dimensional arrays as it is for -one-dimensional arrays. - - <p>Creating the array is simple: using a dynamic-allocation routine like -<code>fftw_malloc</code>, allocate an array big enough to store N -<code>fftw_complex</code> values (for a complex DFT), where N is the product -of the sizes of the array dimensions (i.e. the total number of complex -values in the array). For example, here is code to allocate a -5 × 12 × 27 rank-3 array: -<a name="index-fftw_005fmalloc-118"></a> -<pre class="example"> fftw_complex *an_array; - an_array = (fftw_complex*) fftw_malloc(5*12*27 * sizeof(fftw_complex)); -</pre> - <p>Accessing the array elements, however, is more tricky—you can't -simply use multiple applications of the `<samp><span class="samp">[]</span></samp>' operator like you -could for fixed-size arrays. Instead, you have to explicitly compute -the offset into the array using the formula given earlier for -row-major arrays. For example, to reference the (i,j,k)-th -element of the array allocated above, you would use the expression -<code>an_array[k + 27 * (j + 12 * i)]</code>. - - <p>This pain can be alleviated somewhat by defining appropriate macros, -or, in C++, creating a class and overloading the `<samp><span class="samp">()</span></samp>' operator. -The recent C99 standard provides a way to reinterpret the dynamic -array as a “variable-length” multi-dimensional array amenable to -`<samp><span class="samp">[]</span></samp>', but this feature is not yet widely supported by compilers. -<a name="index-C99-119"></a><a name="index-C_002b_002b-120"></a> -<!-- =========> --> - - </body></html> -