Mediawiki/Erweiterung/Gnuplot

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Die Mediawiki-Erweiterung Gnuplot (auch: GNUPlot) erlaubt die Erzeugung und Anzeige von grafischen Darstellungen. Dabei wird das Programm Gnuplot verwendet.

Installation

1. Voraussetzung ist die Installation des Pakets "gnuplot". 

# apt-get install gnuplot

2. Anlegen der Datei "extensions/Gnuplot.php" und Einfügen des folgenden PHP-Codes (Stand: 8. Februar 2009). 

<?php
/**
 * Parser hook extension adds a <gnuplot> tag and <dataset> tag to wiki markup for rendering gnuplot plots!
 * 
 * 
 * Usage is something like this:
 * <gnuplot>
 * set title "Text"
 * set yrange [0:60]
 * set xtics (0,1,2,3,4,5,6,7,8,9,10)
 * set xrange [0:10]
 * plot <dataset>0 1
 * 2 10
 * 3 15
 * </dataset> using 1:2 title "Burndown" with lines
 * </gnuplot>
 * 
 * Options should be heroicly wide open.. if you can wrap your head around all the possibilities listed in the
 * gnuplot documentation. 
 * 
 **/
 
// Make sure we are being called properly
if( !defined( 'MEDIAWIKI' ) ) {
	echo(" This file is an extension to the MediaWiki software and cannot be used standalone.\n" );
	die( -1 );
}
 
$wgExtensionFunctions[] = "wfGnuplotExtension";
 
/**
 * You should refer to the gnuplot documentation for the different output types
 * Honestly, only image types will work without some other changes
 */
$image_format = "png";
$gnuplot_path   = "/usr/bin/gnuplot";
 
/**
 * The function links its methods as
 * hooks for the Parser
 */
function wfGnuplotExtension() {
	global $wgParser;
	# register the extension with the WikiText parser
	# the first parameter is the name of the new tag.
	# the second parameter is the callback function for
	# processing the text between the tags
	$wgParser->setHook( "dataset", "saveDATA" );
	$wgParser->setHook( "gnuplot", "renderPLOT" );
}
 
 
/**
 * This method setups up the output of the plot script, which 
 * has a few things that we dont want to repeat EVERYTIME someone 
 * wants to make a graph
 *
 * @param String $plot_source - we have to have the full source to wrap
 * @param String $output_filename - we have to tell gnuplot where to output the graph
 * @return the script with output stuff wrapped in it
 */
function wrap_script($plot_source, $output_filename) {
	global $image_format;
	$something  = "set terminal ".$image_format."\n";
	$something .= "set output \"".$output_filename."\"\n";
	$something .= $plot_source;
	return $something;
}
 
/**
 * Caches the command script and calls the gnuplot executable to render the
 * graph image
 *
 * @param String $plot_script
 * @return Nothing.. we assume this all goes correctly.
 */
function renderGnuPlot(&$plot_script) {
	global
	$wgMathDirectory,
	$wgMathPath,
	$wgTmpDirectory,
	$image_format,
	$gnuplot_path;
 
 
	// hash our script
	$script_hash = md5($plot_script);
	// make the output of the command be in the math directory
	$filename = $wgMathDirectory."/plot-".$script_hash.".".$image_format;
 
	//fill in the extras our consumer doesn't care about
	$full_plot_script = wrap_script($plot_script,$filename);
 
	$current_dir = getcwd();
 
	chdir($wgTmpDirectory);
 
	// create temporary file for the plot script
	$winPath = $wgTmpDirectory."/".$script_hash.".plot";
	$fp = fopen($winPath,"a+");
	$w= fputs($fp,$full_plot_script);
	fclose($fp);
 
	// run gnuplot to create our file
	$command = $gnuplot_path." ".$script_hash.".plot ";
	//I had a problem with the status code always being false. so, stopped using it
	$status_code = exec($command);
 
	//delete the plot file
	unlink($wgTmpDirectory."/".$script_hash.".plot");
	chdir($current_dir);
}
 
 
/**
 * Determins if a graph file has already been rendered
 * if not, calls to render one and returns the root host url to the image. 
 *
 * @param String $plot_script
 * @return images/math/plot-.... file reference for the image tag
 */
function getPlotImageURL($plot_script) {
	global
	$wgMathDirectory,
	$wgMathPath,
	$image_format;
 
	//unique our script
	$formula_hash = md5($plot_script);
 
	$filename = 'plot-' . $formula_hash.".".$image_format;
	$full_path_filename = $wgMathDirectory."/".$filename;
 
	if (is_file($full_path_filename)) {
		//nothing to do
		//we've already made this image before
	} else {
		renderGnuPlot($plot_script);
	}
	return $wgMathPath."/".$filename;
}
 
/**
 * The callback function for converting the input text to HTML output
 *
 * @param String $input
 * @param Array<String> $argv
 * @param Parser $parser
 * @return HTML image tag to the graph itself
 */
function renderPLOT( &$input, $argv, &$parser ) {
	//get our parser to finish up its parse and recover the real data-set data (the UNIQ QINU problem)
	$input = $parser->recursiveTagParse( $input );
	$input = $parser->mStripState->unstripBoth($input);
	$url = getPlotImageURL($input);
 
	return "<img src='$url'>";
 
}
 
/**
 * This method takes in the raw tuple input of the dataset, and any arguments, and saves it to a random
 * file on the system. The return is the absolute path to the data file, so that it can be 
 * embedded into the plot command.
 *
 * @param String $input
 * @param Array<String> $argv
 * @param Parser $parser
 * @return unknown
 */
function saveDATA( $input, $argv, &$parser){
	global
	$wgMathDirectory,
	$wgMathPath,
	$wgTmpDirectory;
 
	//make a temp filename with a hash of the input
	$filename = md5($input);
	//we dont wanna create toooo many of these guys either
	if (!is_file($wgTmpDirectory."/".$filename.".dat")) {
		//know where we are
		$current_dir = getcwd();
		//than change it
		chdir($wgTmpDirectory);
 
		// saving this data set as a temporary RANDOM file
		$winPath = $wgTmpDirectory."/".$filename.".dat";
		$fp = fopen($winPath,"a+");
		$w=fputs($fp,$input);
		fclose($fp);
 
		chdir($current_dir);
	}		
	return "\"".$wgTmpDirectory."/".$filename.".dat\"";
}
 
?>

3. Anpassung der Rechte. 

# chown wiki:wiki extensions/gnuplot.php

4. Pfad zu Gnuplot in der Datei "extensions/gnuplot.php" anpassen. 

$gnuplot_path   = "/usr/bin/gnuplot";

5. Einfügen der folgenden Zeile in die Datei "LocalSettings.php". 

## Extension: Gnuplot
require_once('extensions/gnuplot.php');

Die Standardeinstellungen in der Datei "gnuplot.php" sind die folgenden. 

set terminal png color
set size 0.5,0.5

Passendere Einstellungen sind z. B. 

set terminal png color
set size 1.5,1.0

Weblinks

Von «https://mikiwiki.org/mikiwiki/index.php?title=Mediawiki/Erweiterung/Gnuplot&oldid=4554»