... tags
// first converts it to TeX using WeBWorK algebra parser Perl library
// AlgParser.pm, part of the WeBWorK distribution obtained from
// http://webhost.math.rochester.edu/downloadwebwork/
// then converts the TeX to gif images using
// mimetex.cgi obtained from http://www.forkosh.com/mimetex.html authored by
// John Forkosh john@forkosh.com. The mimetex.cgi ELF binary compiled for Linux i386
// as well as AlgParser.pm are included with this distribution.
// Note that there may be patent restrictions on the production of gif images
// in Canada and some parts of Western Europe and Japan until July 2004.
//-------------------------------------------------------------------------
// You will then need to edit your moodle/config.php to invoke mathml_filter.php
//-------------------------------------------------------------------------
function string_file_picture_algebra($imagefile, $tex= "", $height="", $width="", $align="middle") {
// Given the path to a picture file in a course, or a URL,
// this function includes the picture in the page.
global $CFG;
$output = "";
$origtex = $tex;
$style = 'style="border:0px; vertical-align:'.$align.';';
if ($tex) {
$tex = str_replace('&','&',$tex);
$tex = str_replace('<','<',$tex);
$tex = str_replace('>','>',$tex);
$tex = str_replace('"','"',$tex);
$tex = str_replace("\'",''',$tex);
$title = "title=\"$tex\"";
}
if ($height) {
$style .= " height:{$height}px;";
}
if ($width) {
$style .= " width:{$width}px;";
}
$style .= '"';
if ($imagefile) {
if (!file_exists("$CFG->dataroot/filter/algebra/$imagefile") && has_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM))) {
$output .= "wwwroot/filter/algebra/algebradebug.php\">";
} else {
$output .= "wwwroot/filter/algebra/displaytex.php?";
$output .= urlencode($tex) . "\" onclick=\"return openpopup('/filter/algebra/displaytex.php?";
$output .= urlencode($tex) . "', 'popup', 'menubar=0,location=0,scrollbars,";
$output .= "resizable,width=300,height=240', 0);\">";
}
$output .= "slasharguments) { // Use this method if possible for better caching
$output .= "$CFG->wwwroot/filter/algebra/pix.php/$imagefile";
} else {
$output .= "$CFG->wwwroot/filter/algebra/pix.php?file=$imagefile";
}
$output .= "\" $style />";
$output .= "";
} else {
$output .= "Error: must pass URL or course";
}
return $output;
}
function algebra_filter ($courseid, $text) {
global $CFG;
/// Do a quick check using stripos to avoid unnecessary wor
if (!preg_match('/discussion);
# } else if (strstr($scriptname,'discuss.php')) {
# $discussion = get_record("forum_discussions","id",$_GET['d'] );
# } else {
# return $text;
# }
# if ($discussion->forum != 130) {
# return $text;
# }
$text .= ' ';
preg_match_all('/@(@@+)([^@])/',$text,$matches);
for ($i=0;$i some algebraic input expression
// or @@ some algebraic input expression @@
preg_match_all('/(.+?)<\/algebra>|@@(.+?)@@/is', $text, $matches);
for ($i=0; $i','',$algebra);
$algebra = str_replace('','',$algebra);
$algebra = str_replace('','',$algebra);
$algebra = str_replace('','',$algebra);
$align = "middle";
if (preg_match('/^align=bottom /',$algebra)) {
$align = "text-bottom";
$algebra = preg_replace('/^align=bottom /','',$algebra);
} else if (preg_match('/^align=top /',$algebra)) {
$align = "text-top";
$algebra = preg_replace('/^align=top /','',$algebra);
}
$md5 = md5($algebra);
$filename = $md5 . ".gif";
if (! $texcache = get_record("cache_filters","filter","algebra", "md5key", $md5)) {
$algebra = str_replace('<','<',$algebra);
$algebra = str_replace('>','>',$algebra);
$algebra = str_replace('<>','#',$algebra);
$algebra = str_replace('<=','%',$algebra);
$algebra = str_replace('>=','!',$algebra);
$algebra = preg_replace('/([=><%!#] *)-/',"\$1 zeroplace -",$algebra);
$algebra = str_replace('delta','zdelta',$algebra);
$algebra = str_replace('beta','bita',$algebra);
$algebra = str_replace('theta','thita',$algebra);
$algebra = str_replace('zeta','zita',$algebra);
$algebra = str_replace('eta','xeta',$algebra);
$algebra = str_replace('epsilon','zepslon',$algebra);
$algebra = str_replace('upsilon','zupslon',$algebra);
$algebra = preg_replace('!\r\n?!',' ',$algebra);
$algebra = escapeshellarg($algebra);
if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) {
$cmd = "cd $CFG->dirroot\\filter\\algebra & algebra2tex.pl $algebra";
} else {
$cmd = "cd $CFG->dirroot/filter/algebra; ./algebra2tex.pl $algebra";
}
$texexp = `$cmd`;
if (preg_match('/parsehilight/',$texexp)) {
$text = str_replace( $matches[0][$i],"Syntax error: " . $texexp,$text);
} else if ($texexp) {
$texexp = str_replace('zeroplace','',$texexp);
$texexp = str_replace('#','\not= ',$texexp);
$texexp = str_replace('%','\leq ',$texexp);
$texexp = str_replace('!','\geq ',$texexp);
$texexp = str_replace('\left{','{',$texexp);
$texexp = str_replace('\right}','}',$texexp);
$texexp = str_replace('\fun',' ',$texexp);
$texexp = str_replace('infty','\infty',$texexp);
$texexp = str_replace('alpha','\alpha',$texexp);
$texexp = str_replace('gamma','\gamma',$texexp);
$texexp = str_replace('iota','\iota',$texexp);
$texexp = str_replace('kappa','\kappa',$texexp);
$texexp = str_replace('lambda','\lambda',$texexp);
$texexp = str_replace('mu','\mu',$texexp);
$texexp = str_replace('nu','\nu',$texexp);
$texexp = str_replace('xi','\xi',$texexp);
$texexp = str_replace('rho','\rho',$texexp);
$texexp = str_replace('sigma','\sigma',$texexp);
$texexp = str_replace('tau','\tau',$texexp);
$texexp = str_replace('phi','\phi',$texexp);
$texexp = str_replace('chi','\chi',$texexp);
$texexp = str_replace('psi','\psi',$texexp);
$texexp = str_replace('omega','\omega',$texexp);
$texexp = str_replace('zdelta','\delta',$texexp);
$texexp = str_replace('bita','\beta',$texexp);
$texexp = str_replace('thita','\theta',$texexp);
$texexp = str_replace('zita','\zeta',$texexp);
$texexp = str_replace('xeta','\eta',$texexp);
$texexp = str_replace('zepslon','\epsilon',$texexp);
$texexp = str_replace('zupslon','\upsilon',$texexp);
$texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$texexp);
$texexp = str_replace('\mbox{acos}','\mbox{cos}^{-1}',$texexp);
$texexp = str_replace('\mbox{asin}','\mbox{sin}^{-1}',$texexp);
$texexp = str_replace('\mbox{atan}','\mbox{tan}^{-1}',$texexp);
$texexp = str_replace('\mbox{asec}','\mbox{sec}^{-1}',$texexp);
$texexp = str_replace('\mbox{acsc}','\mbox{csc}^{-1}',$texexp);
$texexp = str_replace('\mbox{acot}','\mbox{cot}^{-1}',$texexp);
$texexp = str_replace('\mbox{acosh}','\mbox{cosh}^{-1}',$texexp);
$texexp = str_replace('\mbox{asinh}','\mbox{sinh}^{-1}',$texexp);
$texexp = str_replace('\mbox{atanh}','\mbox{tanh}^{-1}',$texexp);
$texexp = str_replace('\mbox{asech}','\mbox{sech}^{-1}',$texexp);
$texexp = str_replace('\mbox{acsch}','\mbox{csch}^{-1}',$texexp);
$texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp);
//$texexp = preg_replace('/\\\frac{(.+?)}{\\\left\((.+?)\\\right\)}/s','\frac{'."\$1}{\$2}",$texexp);
$texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp);
$texexp = preg_replace('/\\\mbox{abs}\\\left\((.+?)\\\right\)/s',"|\$1|",$texexp);
$texexp = preg_replace('/\\\log\\\left\((.+?),(.+?)\\\right\)/s','\log_{'. "\$2}\\left(\$1\\right)",$texexp);
$texexp = preg_replace('/(\\\cos|\\\sin|\\\tan|\\\sec|\\\csc|\\\cot)([h]*)\\\left\((.+?),(.+?)\\\right\)/s',"\$1\$2^{". "\$4}\\left(\$3\\right)",$texexp);
$texexp = preg_replace('/\\\int\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\int_'. "{\$2}^{\$3}\$1 ",$texexp);
$texexp = preg_replace('/\\\int\\\left\((.+?d[a-z])\\\right\)/s','\int '. "\$1 ",$texexp);
$texexp = preg_replace('/\\\lim\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\lim_'. "{\$2\\to \$3}\$1 ",$texexp);
$texcache->filter = 'algebra';
$texcache->version = 1;
$texcache->md5key = $md5;
$texcache->rawtext = addslashes($texexp);
$texcache->timemodified = time();
insert_record("cache_filters",$texcache, false);
$text = str_replace( $matches[0][$i], string_file_picture_algebra($filename, $texexp, '', '', $align), $text);
} else {
$text = str_replace( $matches[0][$i],"Undetermined error: ",$text);
}
} else {
$text = str_replace( $matches[0][$i], string_file_picture_algebra($filename, $texcache->rawtext), $text);
}
}
return $text;
}
?>