David Mudrak
dcfffe3072
The only option passed at the moment is the original format in which the user inserted the text. Other options can be added later if/when needed.
244 lines
12 KiB
PHP
244 lines
12 KiB
PHP
<?php
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// This file is part of Moodle - http://moodle.org/
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//
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// Moodle is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// Moodle is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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/**
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* Moodle - Filter for converting simple calculator-type algebraic
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* expressions to cached gif images
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*
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* @package filter
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* @subpackage algebra
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* @copyright 2004 Zbigniew Fiedorowicz fiedorow@math.ohio-state.edu
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* Originally based on code provided by Bruno Vernier bruno@vsbeducation.ca
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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defined('MOODLE_INTERNAL') || die();
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//-------------------------------------------------------------------------
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// NOTE: This Moodle text filter converts algebraic expressions delimited
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// by either @@...@@ or by <algebra...>...</algebra> tags
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// first converts it to TeX using WeBWorK algebra parser Perl library
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// AlgParser.pm, part of the WeBWorK distribution obtained from
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// http://webhost.math.rochester.edu/downloadwebwork/
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// then converts the TeX to gif images using
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// mimetex.cgi obtained from http://www.forkosh.com/mimetex.html authored by
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// John Forkosh john@forkosh.com. The mimetex.cgi ELF binary compiled for Linux i386
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// as well as AlgParser.pm are included with this distribution.
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// Note that there may be patent restrictions on the production of gif images
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// in Canada and some parts of Western Europe and Japan until July 2004.
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//-------------------------------------------------------------------------
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// You will then need to edit your moodle/config.php to invoke mathml_filter.php
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//-------------------------------------------------------------------------
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function filter_algebra_image($imagefile, $tex= "", $height="", $width="", $align="middle") {
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// Given the path to a picture file in a course, or a URL,
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// this function includes the picture in the page.
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global $CFG, $OUTPUT;
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$output = "";
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$origtex = $tex;
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$style = 'style="border:0px; vertical-align:'.$align.';';
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if ($tex) {
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$tex = str_replace('&','&',$tex);
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$tex = str_replace('<','<',$tex);
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$tex = str_replace('>','>',$tex);
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$tex = str_replace('"','"',$tex);
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$tex = str_replace("\'",''',$tex);
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$title = "title=\"$tex\"";
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}
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if ($height) {
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$style .= " height:{$height}px;";
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}
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if ($width) {
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$style .= " width:{$width}px;";
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}
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$style .= '"';
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if ($imagefile) {
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$anchorcontents .= "<img $title alt=\"".s($origtex)."\" src=\"";
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if ($CFG->slasharguments) { // Use this method if possible for better caching
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$anchorcontents .= "$CFG->wwwroot/filter/algebra/pix.php/$imagefile";
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} else {
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$anchorcontents .= "$CFG->wwwroot/filter/algebra/pix.php?file=$imagefile";
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}
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$anchorcontents .= "\" $style />";
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$link = $action = null;
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if (!file_exists("$CFG->dataroot/filter/algebra/$imagefile") && has_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM))) {
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$link = '/filter/algebra/algebradebug.php';
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} else {
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$link = '/filter/algebra/displaytex.php?'.urlencode($tex);
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$action = new popup_action('click', $link, 'popup', array('height'=>300,'width'=>240));
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}
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$output .= $OUTPUT->action_link($link, $anchorcontents, $action, array('title'=>'TeX'));
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} else {
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$output .= "Error: must pass URL or course";
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}
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return $output;
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}
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class filter_algebra extends moodle_text_filter {
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function filter($text, array $options = array()){
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global $CFG, $DB;
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/// Do a quick check using stripos to avoid unnecessary wor
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if (!preg_match('/<algebra/i',$text) && !strstr($text,'@@')) {
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return $text;
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}
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//restrict filtering to forum 130 (Maths Tools on moodle.org)
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# $scriptname = $_SERVER['SCRIPT_NAME'];
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# if (!strstr($scriptname,'/forum/')) {
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# return $text;
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# }
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# if (strstr($scriptname,'post.php')) {
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# $parent = forum_get_post_full($_GET['reply']);
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# $discussion = $DB->get_record("forum_discussions",array("id"=>$parent->discussion));
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# } else if (strstr($scriptname,'discuss.php')) {
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# $discussion = $DB->get_record("forum_discussions",array("id"=>$_GET['d']));
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# } else {
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# return $text;
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# }
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# if ($discussion->forum != 130) {
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# return $text;
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# }
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$text .= ' ';
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preg_match_all('/@(@@+)([^@])/',$text,$matches);
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for ($i=0;$i<count($matches[0]);$i++) {
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$replacement = str_replace('@','@',$matches[1][$i]).$matches[2][$i];
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$text = str_replace($matches[0][$i],$replacement,$text);
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}
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// <algebra> some algebraic input expression </algebra>
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// or @@ some algebraic input expression @@
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preg_match_all('/<algebra>(.+?)<\/algebra>|@@(.+?)@@/is', $text, $matches);
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for ($i=0; $i<count($matches[0]); $i++) {
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$algebra = $matches[1][$i] . $matches[2][$i];
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$algebra = str_replace('<nolink>','',$algebra);
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$algebra = str_replace('</nolink>','',$algebra);
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$algebra = str_replace('<span class="nolink">','',$algebra);
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$algebra = str_replace('</span>','',$algebra);
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$align = "middle";
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if (preg_match('/^align=bottom /',$algebra)) {
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$align = "text-bottom";
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$algebra = preg_replace('/^align=bottom /','',$algebra);
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} else if (preg_match('/^align=top /',$algebra)) {
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$align = "text-top";
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$algebra = preg_replace('/^align=top /','',$algebra);
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}
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$md5 = md5($algebra);
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$filename = $md5 . ".gif";
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if (! $texcache = $DB->get_record("cache_filters",array("filter"=>"algebra", "md5key"=>$md5))) {
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$algebra = str_replace('<','<',$algebra);
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$algebra = str_replace('>','>',$algebra);
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$algebra = str_replace('<>','#',$algebra);
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$algebra = str_replace('<=','%',$algebra);
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$algebra = str_replace('>=','!',$algebra);
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$algebra = preg_replace('/([=><%!#] *)-/',"\$1 zeroplace -",$algebra);
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$algebra = str_replace('delta','zdelta',$algebra);
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$algebra = str_replace('beta','bita',$algebra);
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$algebra = str_replace('theta','thita',$algebra);
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$algebra = str_replace('zeta','zita',$algebra);
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$algebra = str_replace('eta','xeta',$algebra);
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$algebra = str_replace('epsilon','zepslon',$algebra);
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$algebra = str_replace('upsilon','zupslon',$algebra);
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$algebra = preg_replace('!\r\n?!',' ',$algebra);
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$algebra = escapeshellarg($algebra);
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if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) {
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$cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl $algebra";
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} else {
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$cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl $algebra";
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}
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$texexp = `$cmd`;
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if (preg_match('/parsehilight/',$texexp)) {
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$text = str_replace( $matches[0][$i],"<b>Syntax error:</b> " . $texexp,$text);
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} else if ($texexp) {
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$texexp = str_replace('zeroplace','',$texexp);
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$texexp = str_replace('#','\not= ',$texexp);
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$texexp = str_replace('%','\leq ',$texexp);
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$texexp = str_replace('!','\geq ',$texexp);
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$texexp = str_replace('\left{','{',$texexp);
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$texexp = str_replace('\right}','}',$texexp);
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$texexp = str_replace('\fun',' ',$texexp);
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$texexp = str_replace('infty','\infty',$texexp);
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$texexp = str_replace('alpha','\alpha',$texexp);
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$texexp = str_replace('gamma','\gamma',$texexp);
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$texexp = str_replace('iota','\iota',$texexp);
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$texexp = str_replace('kappa','\kappa',$texexp);
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$texexp = str_replace('lambda','\lambda',$texexp);
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$texexp = str_replace('mu','\mu',$texexp);
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$texexp = str_replace('nu','\nu',$texexp);
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$texexp = str_replace('xi','\xi',$texexp);
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$texexp = str_replace('rho','\rho',$texexp);
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$texexp = str_replace('sigma','\sigma',$texexp);
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$texexp = str_replace('tau','\tau',$texexp);
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$texexp = str_replace('phi','\phi',$texexp);
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$texexp = str_replace('chi','\chi',$texexp);
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$texexp = str_replace('psi','\psi',$texexp);
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$texexp = str_replace('omega','\omega',$texexp);
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$texexp = str_replace('zdelta','\delta',$texexp);
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$texexp = str_replace('bita','\beta',$texexp);
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$texexp = str_replace('thita','\theta',$texexp);
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$texexp = str_replace('zita','\zeta',$texexp);
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$texexp = str_replace('xeta','\eta',$texexp);
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$texexp = str_replace('zepslon','\epsilon',$texexp);
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$texexp = str_replace('zupslon','\upsilon',$texexp);
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$texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$texexp);
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$texexp = str_replace('\mbox{acos}','\mbox{cos}^{-1}',$texexp);
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$texexp = str_replace('\mbox{asin}','\mbox{sin}^{-1}',$texexp);
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$texexp = str_replace('\mbox{atan}','\mbox{tan}^{-1}',$texexp);
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$texexp = str_replace('\mbox{asec}','\mbox{sec}^{-1}',$texexp);
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$texexp = str_replace('\mbox{acsc}','\mbox{csc}^{-1}',$texexp);
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$texexp = str_replace('\mbox{acot}','\mbox{cot}^{-1}',$texexp);
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$texexp = str_replace('\mbox{acosh}','\mbox{cosh}^{-1}',$texexp);
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$texexp = str_replace('\mbox{asinh}','\mbox{sinh}^{-1}',$texexp);
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$texexp = str_replace('\mbox{atanh}','\mbox{tanh}^{-1}',$texexp);
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$texexp = str_replace('\mbox{asech}','\mbox{sech}^{-1}',$texexp);
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$texexp = str_replace('\mbox{acsch}','\mbox{csch}^{-1}',$texexp);
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$texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp);
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//$texexp = preg_replace('/\\\frac{(.+?)}{\\\left\((.+?)\\\right\)}/s','\frac{'."\$1}{\$2}",$texexp);
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$texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp);
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$texexp = preg_replace('/\\\mbox{abs}\\\left\((.+?)\\\right\)/s',"|\$1|",$texexp);
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$texexp = preg_replace('/\\\log\\\left\((.+?),(.+?)\\\right\)/s','\log_{'. "\$2}\\left(\$1\\right)",$texexp);
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$texexp = preg_replace('/(\\\cos|\\\sin|\\\tan|\\\sec|\\\csc|\\\cot)([h]*)\\\left\((.+?),(.+?)\\\right\)/s',"\$1\$2^{". "\$4}\\left(\$3\\right)",$texexp);
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$texexp = preg_replace('/\\\int\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\int_'. "{\$2}^{\$3}\$1 ",$texexp);
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$texexp = preg_replace('/\\\int\\\left\((.+?d[a-z])\\\right\)/s','\int '. "\$1 ",$texexp);
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$texexp = preg_replace('/\\\lim\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\lim_'. "{\$2\\to \$3}\$1 ",$texexp);
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$texcache->filter = 'algebra';
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$texcache->version = 1;
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$texcache->md5key = $md5;
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$texcache->rawtext = $texexp;
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$texcache->timemodified = time();
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$DB->insert_record("cache_filters", $texcache, false);
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$text = str_replace( $matches[0][$i], filter_algebra_image($filename, $texexp, '', '', $align), $text);
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} else {
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$text = str_replace( $matches[0][$i],"<b>Undetermined error:</b> ",$text);
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}
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} else {
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$text = str_replace( $matches[0][$i], filter_algebra_image($filename, $texcache->rawtext), $text);
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}
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}
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return $text;
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}
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}
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