112 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
		
		
			
		
	
	
			112 lines
		
	
	
		
			4.9 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 of Fortran? (FFTW 3.3.10)</title> | ||
|  | 
 | ||
|  | <meta name="description" content="Wisdom of Fortran? (FFTW 3.3.10)"> | ||
|  | <meta name="keywords" content="Wisdom of 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="Calling-FFTW-from-Legacy-Fortran.html" rel="up" title="Calling FFTW from Legacy Fortran"> | ||
|  | <link href="Upgrading-from-FFTW-version-2.html" rel="next" title="Upgrading from FFTW version 2"> | ||
|  | <link href="Fortran-Examples.html" rel="prev" title="Fortran Examples"> | ||
|  | <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-of-Fortran_003f"></span><div class="header"> | ||
|  | <p> | ||
|  | Previous: <a href="Fortran-Examples.html" accesskey="p" rel="prev">Fortran Examples</a>, Up: <a href="Calling-FFTW-from-Legacy-Fortran.html" accesskey="u" rel="up">Calling FFTW from Legacy 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-of-Fortran_003f-1"></span><h3 class="section">8.5 Wisdom of Fortran?</h3> | ||
|  | 
 | ||
|  | <p>In this section, we discuss how one can import/export FFTW wisdom | ||
|  | (saved plans) to/from a Fortran program; we assume that the reader is | ||
|  | already familiar with wisdom, as described in <a href="Words-of-Wisdom_002dSaving-Plans.html">Words of Wisdom-Saving Plans</a>. | ||
|  | </p> | ||
|  | <span id="index-portability-8"></span> | ||
|  | <p>The basic problem is that is difficult to (portably) pass files and | ||
|  | strings between Fortran and C, so we cannot provide a direct Fortran | ||
|  | equivalent to the <code>fftw_export_wisdom_to_file</code>, etcetera, | ||
|  | functions.  Fortran interfaces <em>are</em> provided for the functions | ||
|  | that do not take file/string arguments, however: | ||
|  | <code>dfftw_import_system_wisdom</code>, <code>dfftw_import_wisdom</code>, | ||
|  | <code>dfftw_export_wisdom</code>, and <code>dfftw_forget_wisdom</code>. | ||
|  | <span id="index-dfftw_005fimport_005fsystem_005fwisdom"></span> | ||
|  | <span id="index-dfftw_005fimport_005fwisdom"></span> | ||
|  | <span id="index-dfftw_005fexport_005fwisdom"></span> | ||
|  | <span id="index-dfftw_005fforget_005fwisdom"></span> | ||
|  | </p> | ||
|  | 
 | ||
|  | <p>So, for example, to import the system-wide wisdom, you would do: | ||
|  | </p> | ||
|  | <div class="example"> | ||
|  | <pre class="example">        integer isuccess | ||
|  |         call dfftw_import_system_wisdom(isuccess) | ||
|  | </pre></div> | ||
|  | 
 | ||
|  | <p>As usual, the C return value is turned into a first parameter; | ||
|  | <code>isuccess</code> is non-zero on success and zero on failure (e.g. if | ||
|  | there is no system wisdom installed). | ||
|  | </p> | ||
|  | <p>If you want to import/export wisdom from/to an arbitrary file or | ||
|  | elsewhere, you can employ the generic <code>dfftw_import_wisdom</code> and | ||
|  | <code>dfftw_export_wisdom</code> functions, for which you must supply a | ||
|  | subroutine to read/write one character at a time.  The FFTW package | ||
|  | contains an example file <code>doc/f77_wisdom.f</code> demonstrating how to | ||
|  | implement <code>import_wisdom_from_file</code> and | ||
|  | <code>export_wisdom_to_file</code> subroutines in this way.  (These routines | ||
|  | cannot be compiled into the FFTW library itself, lest all FFTW-using | ||
|  | programs be required to link with the Fortran I/O library.) | ||
|  | </p> | ||
|  | 
 | ||
|  | 
 | ||
|  | </body> | ||
|  | </html> |