106 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
		
		
			
		
	
	
			106 lines
		
	
	
		
			5.1 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 File Export/Import from Fortran (FFTW 3.3.10)</title> | ||
|  | 
 | ||
|  | <meta name="description" content="Wisdom File Export/Import from Fortran (FFTW 3.3.10)"> | ||
|  | <meta name="keywords" content="Wisdom File 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="Wisdom-String-Export_002fImport-from-Fortran.html" rel="next" title="Wisdom String Export/Import from Fortran"> | ||
|  | <link href="Accessing-the-wisdom-API-from-Fortran.html" rel="prev" title="Accessing the wisdom API 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-File-Export_002fImport-from-Fortran"></span><div class="header"> | ||
|  | <p> | ||
|  | Next: <a href="Wisdom-String-Export_002fImport-from-Fortran.html" accesskey="n" rel="next">Wisdom String Export/Import from Fortran</a>, Previous: <a href="Accessing-the-wisdom-API-from-Fortran.html" accesskey="p" rel="prev">Accessing the wisdom API 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-File-Export_002fImport-from-Fortran-1"></span><h4 class="subsection">7.6.1 Wisdom File Export/Import from Fortran</h4> | ||
|  | 
 | ||
|  | <span id="index-fftw_005fimport-wisdom_005ffrom_005ffilename"></span> | ||
|  | <span id="index-fftw_005fexport_005fwisdom_005fto_005ffilename-2"></span> | ||
|  | <p>The easiest way to export and import wisdom is to do so using | ||
|  | <code>fftw_export_wisdom_to_filename</code> and | ||
|  | <code>fftw_wisdom_from_filename</code>.  The only trick is that these | ||
|  | require you to pass a C string, which is an array of type | ||
|  | <code>CHARACTER(C_CHAR)</code> that is terminated by <code>C_NULL_CHAR</code>. | ||
|  | You can call them like this: | ||
|  | </p> | ||
|  | <div class="example"> | ||
|  | <pre class="example">  integer(C_INT) :: ret | ||
|  |   ret = fftw_export_wisdom_to_filename(C_CHAR_'my_wisdom.dat' // C_NULL_CHAR) | ||
|  |   if (ret .eq. 0) stop 'error exporting wisdom to file' | ||
|  |   ret = fftw_import_wisdom_from_filename(C_CHAR_'my_wisdom.dat' // C_NULL_CHAR) | ||
|  |   if (ret .eq. 0) stop 'error importing wisdom from file' | ||
|  | </pre></div> | ||
|  | 
 | ||
|  | <p>Note that prepending ‘<samp>C_CHAR_</samp>’ is needed to specify that the | ||
|  | literal string is of kind <code>C_CHAR</code>, and we null-terminate the | ||
|  | string by appending ‘<samp>// C_NULL_CHAR</samp>’.  These functions return an | ||
|  | <code>integer(C_INT)</code> (<code>ret</code>) which is <code>0</code> if an error | ||
|  | occurred during export/import and nonzero otherwise. | ||
|  | </p> | ||
|  | <p>It is also possible to use the lower-level routines | ||
|  | <code>fftw_export_wisdom_to_file</code> and | ||
|  | <code>fftw_import_wisdom_from_file</code>, which accept parameters of the C | ||
|  | type <code>FILE*</code>, expressed in Fortran as <code>type(C_PTR)</code>. | ||
|  | However, you are then responsible for creating the <code>FILE*</code> | ||
|  | yourself.  You can do this by using <code>iso_c_binding</code> to define | ||
|  | Fortran intefaces for the C library functions <code>fopen</code> and | ||
|  | <code>fclose</code>, which is a bit strange in Fortran but workable. | ||
|  | </p> | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | </body> | ||
|  | </html> |