140 lines
6.1 KiB
HTML
140 lines
6.1 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- This manual is for FFTW
|
|
(version 3.3.10, 10 December 2020).
|
|
|
|
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. -->
|
|
<!-- Created by GNU Texinfo 6.7, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<title>Wisdom Generic Export/Import from Fortran (FFTW 3.3.10)</title>
|
|
|
|
<meta name="description" content="Wisdom Generic Export/Import from Fortran (FFTW 3.3.10)">
|
|
<meta name="keywords" content="Wisdom Generic Export/Import from Fortran (FFTW 3.3.10)">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<link href="index.html" rel="start" title="Top">
|
|
<link href="Concept-Index.html" rel="index" title="Concept Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="Accessing-the-wisdom-API-from-Fortran.html" rel="up" title="Accessing the wisdom API from Fortran">
|
|
<link href="Defining-an-FFTW-module.html" rel="next" title="Defining an FFTW module">
|
|
<link href="Wisdom-String-Export_002fImport-from-Fortran.html" rel="prev" title="Wisdom String Export/Import from Fortran">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
kbd {font-style: oblique}
|
|
pre.display {font-family: inherit}
|
|
pre.format {font-family: inherit}
|
|
pre.menu-comment {font-family: serif}
|
|
pre.menu-preformatted {font-family: serif}
|
|
span.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<span id="Wisdom-Generic-Export_002fImport-from-Fortran"></span><div class="header">
|
|
<p>
|
|
Previous: <a href="Wisdom-String-Export_002fImport-from-Fortran.html" accesskey="p" rel="prev">Wisdom String Export/Import from Fortran</a>, Up: <a href="Accessing-the-wisdom-API-from-Fortran.html" accesskey="u" rel="up">Accessing the wisdom API from Fortran</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
<hr>
|
|
<span id="Wisdom-Generic-Export_002fImport-from-Fortran-1"></span><h4 class="subsection">7.6.3 Wisdom Generic Export/Import from Fortran</h4>
|
|
|
|
<p>The most generic wisdom export/import functions allow you to provide
|
|
an arbitrary callback function to read/write one character at a time
|
|
in any way you want. However, your callback function must be written
|
|
in a special way, using the <code>bind(C)</code> attribute to be passed to a
|
|
C interface.
|
|
</p>
|
|
<span id="index-fftw_005fexport_005fwisdom-1"></span>
|
|
<p>In particular, to call the generic wisdom export function
|
|
<code>fftw_export_wisdom</code>, you would write a callback subroutine of the form:
|
|
</p>
|
|
<div class="example">
|
|
<pre class="example"> subroutine my_write_char(c, p) bind(C)
|
|
use, intrinsic :: iso_c_binding
|
|
character(C_CHAR), value :: c
|
|
type(C_PTR), value :: p
|
|
<em>...write c...</em>
|
|
end subroutine my_write_char
|
|
</pre></div>
|
|
|
|
<p>Given such a subroutine (along with the corresponding interface definition), you could then export wisdom using:
|
|
</p>
|
|
<span id="index-c_005ffunloc"></span>
|
|
<div class="example">
|
|
<pre class="example"> call fftw_export_wisdom(c_funloc(my_write_char), p)
|
|
</pre></div>
|
|
|
|
<span id="index-c_005floc"></span>
|
|
<span id="index-c_005ff_005fpointer-4"></span>
|
|
<p>The standard <code>c_funloc</code> intrinsic converts a Fortran
|
|
<code>bind(C)</code> subroutine into a C function pointer. The parameter
|
|
<code>p</code> is a <code>type(C_PTR)</code> to any arbitrary data that you want
|
|
to pass to <code>my_write_char</code> (or <code>C_NULL_PTR</code> if none). (Note
|
|
that you can get a C pointer to Fortran data using the intrinsic
|
|
<code>c_loc</code>, and convert it back to a Fortran pointer in
|
|
<code>my_write_char</code> using <code>c_f_pointer</code>.)
|
|
</p>
|
|
<p>Similarly, to use the generic <code>fftw_import_wisdom</code>, you would
|
|
define a callback function of the form:
|
|
</p>
|
|
<span id="index-fftw_005fimport_005fwisdom-1"></span>
|
|
<div class="example">
|
|
<pre class="example"> integer(C_INT) function my_read_char(p) bind(C)
|
|
use, intrinsic :: iso_c_binding
|
|
type(C_PTR), value :: p
|
|
character :: c
|
|
<em>...read a character c...</em>
|
|
my_read_char = ichar(c, C_INT)
|
|
end function my_read_char
|
|
|
|
....
|
|
|
|
integer(C_INT) :: ret
|
|
ret = fftw_import_wisdom(c_funloc(my_read_char), p)
|
|
if (ret .eq. 0) stop 'error importing wisdom'
|
|
</pre></div>
|
|
|
|
<p>Your function can return <code>-1</code> if the end of the input is reached.
|
|
Again, <code>p</code> is an arbitrary <code>type(C_PTR</code> that is passed
|
|
through to your function. <code>fftw_import_wisdom</code> returns <code>0</code>
|
|
if an error occurred and nonzero otherwise.
|
|
</p>
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Previous: <a href="Wisdom-String-Export_002fImport-from-Fortran.html" accesskey="p" rel="prev">Wisdom String Export/Import from Fortran</a>, Up: <a href="Accessing-the-wisdom-API-from-Fortran.html" accesskey="u" rel="up">Accessing the wisdom API from Fortran</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
|
|
</div>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|