comparison fft/fftw/fftw-3.3.4/doc/html/Wisdom-of-Fortran_003f.html @ 19:26056e866c29

Add FFTW to comparison table
author Chris Cannam
date Tue, 06 Oct 2015 13:08:39 +0100
parents
children
comparison
equal deleted inserted replaced
18:8db794ca3e0b 19:26056e866c29
1 <html lang="en">
2 <head>
3 <title>Wisdom of Fortran? - FFTW 3.3.4</title>
4 <meta http-equiv="Content-Type" content="text/html">
5 <meta name="description" content="FFTW 3.3.4">
6 <meta name="generator" content="makeinfo 4.13">
7 <link title="Top" rel="start" href="index.html#Top">
8 <link rel="up" href="Calling-FFTW-from-Legacy-Fortran.html#Calling-FFTW-from-Legacy-Fortran" title="Calling FFTW from Legacy Fortran">
9 <link rel="prev" href="Fortran-Examples.html#Fortran-Examples" title="Fortran Examples">
10 <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
11 <!--
12 This manual is for FFTW
13 (version 3.3.4, 20 September 2013).
14
15 Copyright (C) 2003 Matteo Frigo.
16
17 Copyright (C) 2003 Massachusetts Institute of Technology.
18
19 Permission is granted to make and distribute verbatim copies of
20 this manual provided the copyright notice and this permission
21 notice are preserved on all copies.
22
23 Permission is granted to copy and distribute modified versions of
24 this manual under the conditions for verbatim copying, provided
25 that the entire resulting derived work is distributed under the
26 terms of a permission notice identical to this one.
27
28 Permission is granted to copy and distribute translations of this
29 manual into another language, under the above conditions for
30 modified versions, except that this permission notice may be
31 stated in a translation approved by the Free Software Foundation.
32 -->
33 <meta http-equiv="Content-Style-Type" content="text/css">
34 <style type="text/css"><!--
35 pre.display { font-family:inherit }
36 pre.format { font-family:inherit }
37 pre.smalldisplay { font-family:inherit; font-size:smaller }
38 pre.smallformat { font-family:inherit; font-size:smaller }
39 pre.smallexample { font-size:smaller }
40 pre.smalllisp { font-size:smaller }
41 span.sc { font-variant:small-caps }
42 span.roman { font-family:serif; font-weight:normal; }
43 span.sansserif { font-family:sans-serif; font-weight:normal; }
44 --></style>
45 </head>
46 <body>
47 <div class="node">
48 <a name="Wisdom-of-Fortran%3f"></a>
49 <a name="Wisdom-of-Fortran_003f"></a>
50 <p>
51 Previous:&nbsp;<a rel="previous" accesskey="p" href="Fortran-Examples.html#Fortran-Examples">Fortran Examples</a>,
52 Up:&nbsp;<a rel="up" accesskey="u" href="Calling-FFTW-from-Legacy-Fortran.html#Calling-FFTW-from-Legacy-Fortran">Calling FFTW from Legacy Fortran</a>
53 <hr>
54 </div>
55
56 <h3 class="section">8.5 Wisdom of Fortran?</h3>
57
58 <p>In this section, we discuss how one can import/export FFTW wisdom
59 (saved plans) to/from a Fortran program; we assume that the reader is
60 already familiar with wisdom, as described in <a href="Words-of-Wisdom_002dSaving-Plans.html#Words-of-Wisdom_002dSaving-Plans">Words of Wisdom-Saving Plans</a>.
61
62 <p><a name="index-portability-601"></a>The basic problem is that is difficult to (portably) pass files and
63 strings between Fortran and C, so we cannot provide a direct Fortran
64 equivalent to the <code>fftw_export_wisdom_to_file</code>, etcetera,
65 functions. Fortran interfaces <em>are</em> provided for the functions
66 that do not take file/string arguments, however:
67 <code>dfftw_import_system_wisdom</code>, <code>dfftw_import_wisdom</code>,
68 <code>dfftw_export_wisdom</code>, and <code>dfftw_forget_wisdom</code>.
69 <a name="index-dfftw_005fimport_005fsystem_005fwisdom-602"></a><a name="index-dfftw_005fimport_005fwisdom-603"></a><a name="index-dfftw_005fexport_005fwisdom-604"></a><a name="index-dfftw_005fforget_005fwisdom-605"></a>
70
71 <p>So, for example, to import the system-wide wisdom, you would do:
72
73 <pre class="example"> integer isuccess
74 call dfftw_import_system_wisdom(isuccess)
75 </pre>
76 <p>As usual, the C return value is turned into a first parameter;
77 <code>isuccess</code> is non-zero on success and zero on failure (e.g. if
78 there is no system wisdom installed).
79
80 <p>If you want to import/export wisdom from/to an arbitrary file or
81 elsewhere, you can employ the generic <code>dfftw_import_wisdom</code> and
82 <code>dfftw_export_wisdom</code> functions, for which you must supply a
83 subroutine to read/write one character at a time. The FFTW package
84 contains an example file <code>doc/f77_wisdom.f</code> demonstrating how to
85 implement <code>import_wisdom_from_file</code> and
86 <code>export_wisdom_to_file</code> subroutines in this way. (These routines
87 cannot be compiled into the FFTW library itself, lest all FFTW-using
88 programs be required to link with the Fortran I/O library.)
89
90 </body></html>
91