Permalink
Browse files

Added debugger for algebra filter

  • Loading branch information...
1 parent 2ab7692 commit 9b361d24b3457e9295eab342c2c39e6579331727 fiedorow committed Feb 19, 2004
Showing with 270 additions and 1 deletion.
  1. +270 −0 filter/algebra/algebradebug.php
  2. +0 −1 filter/algebra/filter.php
@@ -0,0 +1,270 @@
+<?PHP // $Id$
+ // This function fetches math. images from the data directory
+ // If not, it obtains the corresponding TeX expression from the cache_tex db table
+ // and uses mimeTeX to create the image file
+
+ $nomoodlecookie = true; // Because it interferes with caching
+
+ require_once("../../config.php");
+
+
+ $CFG->texfilterdir = "filter/tex";
+ $CFG->algebrafilterdir = "filter/algebra";
+ $CFG->algebraimagedir = "filter/algebra";
+
+ error_reporting(E_ALL);
+ $query = urldecode($_SERVER['QUERY_STRING']);
+
+ if ($query) {
+ $output = $query;
+ $splitpos = strpos($query,'&')-8;
+ $algebra = substr($query,8,$splitpos);
+ $md5 = md5($algebra);
+ if (strpos($query,'ShowDB') || strpos($query,'DeleteDB')) {
+ $texcache = get_record("cache_filters","filter","algebra", "md5key", $md5);
+ }
+ if (strpos($query,'ShowDB')) {
+ if ($texcache) {
+ $output = "DB cache_filters entry for $algebra\n";
+ $output .= "id = $texcache->id\n";
+ $output .= "filter = $texcache->filter\n";
+ $output .= "version = $texcache->version\n";
+ $output .= "md5key = $texcache->md5key\n";
+ $output .= "rawtext = $texcache->rawtext\n";
+ $output .= "timemodified = $texcache->timemodified\n";
+ } else {
+ $output = "DB cache_filters entry for $algebra not found\n";
+ }
+ }
+ if (strpos($query,'DeleteDB')) {
+ if ($texcache) {
+ $output = "Deleting DB cache_filters entry for $algebra\n";
+ $result = delete_records("cache_filters","id",$texcache->id);
+ if ($result) {
+ $result = 1;
+ } else {
+ $result = 0;
+ }
+ $output .= "Number of records deleted = $result\n";
+ } else {
+ $output = "Could not delete DB cache_filters entry for $algebra\nbecause it could not be found.\n";
+ }
+ }
+ if (strpos($query,'TeXStage1')) {
+ $output = algebra2tex($algebra);
+ }
+ if (strpos($query,'TeXStage2')) {
+ $output = algebra2tex($algebra);
+ $output = refineTeX($output);
+ }
+ if (strpos($query,'ShowImage')) {
+ $output = algebra2tex($algebra);
+ $output = refineTeX($output);
+ tex2image($output);
+ } else {
+ outputText($output);
+ }
+ exit;
+ }
+
+function algebra2tex($algebra) {
+ Global $CFG;
+ $algebra = str_replace('&lt;','<',$algebra);
+ $algebra = str_replace('&gt;','>',$algebra);
+ $algebra = str_replace('<>','#',$algebra);
+ $algebra = str_replace('<=','%',$algebra);
+ $algebra = str_replace('>=','!',$algebra);
+ $algebra = preg_replace('!\r\n?!',' ',$algebra);
+ if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) {
+ $algebra = "\"". str_replace('"','\"',$algebra) . "\"";
+ $cmd = "cd $CFG->dirroot/$CFG->algebrafilterdir & algebra2tex.pl $algebra";
+ } else {
+ $algebra = escapeshellarg($algebra);
+ $cmd = "cd $CFG->dirroot/$CFG->algebrafilterdir; ./algebra2tex.pl $algebra";
+ }
+ $texexp = `$cmd`;
+ return $texexp;
+}
+
+function refineTeX($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);
+ $texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$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);
+ $texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$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);
+ return $texexp;
+}
+
+function outputText($texexp) {
+ header("Content-type: text/html");
+ echo "<html><body><pre>\n";
+ if ($texexp) {
+ $texexp = str_replace('<','&lt;',$texexp);
+ $texexp = str_replace('>','&gt;',$texexp);
+ $texexp = str_replace('"','&quot;',$texexp);
+ echo "$texexp\n\n";
+ } else {
+ echo "No text output available\n\n";
+ }
+ echo "</pre></body></html>\n";
+}
+
+function tex2image($texexp) {
+ global $CFG;
+ if ($texexp) {
+ $texexp = '\Large ' . $texexp;
+ $lifetime = 86400;
+ $image = md5($texexp) . ".gif";
+ $filetype = 'image/gif';
+ if (!file_exists("$CFG->dataroot/$CFG->algebraimagedir")) {
+ make_upload_directory($CFG->algebraimagedir);
+ }
+ $pathname = "$CFG->dataroot/$CFG->algebraimagedir/$image";
+ $windows = 0;
+ switch (PHP_OS) {
+ case "Linux":
+ $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.linux -e $pathname ". escapeshellarg($texexp);
+ break;
+ case "WINNT":
+ case "WIN32":
+ case "Windows":
+ $windows = 1;
+ $texexp = str_replace('"','\"',$texexp);
+ $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.exe -e $pathname \"$texexp\"";
+ break;
+ case "Darwin":
+ $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin -e $pathname ". escapeshellarg($texexp);
+ break;
+ }
+ system($cmd);
+ }
+ if ($texexp && file_exists($pathname)) {
+ $lastmodified = filemtime($pathname);
+ header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
+ header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
+ header("Cache-control: max_age = $lifetime"); // a day
+ header("Pragma: ");
+ header("Content-disposition: inline; filename=$image");
+ header("Content-length: ".filesize($pathname));
+ header("Content-type: $filetype");
+ readfile("$pathname");
+ } else {
+ if (!$windows) {
+ $cmd = "$cmd 2>&1";
+ echo `$cmd` . "<br>\n";
+ }
+ echo "Image not found!";
+ }
+}
+?>
+
+<html>
+<head><title>Algebra Filter Debugger</title></head>
+<body>
+<?PHP
+ require_once("../../config.php");
+ $filename = "$CFG->dirroot/filter/algebra/pix.php";
+ $PHP_OS = PHP_OS;
+ $handle = fopen($filename,"r");
+ $contents = fread($handle, filesize($filename));
+ fclose($handle);
+ if (!strpos($contents,'case "'. $PHP_OS . '":')) {
+ echo "<b>WARNING!</b> case \"$PHP_OS\": NOT found in pix.php!!!<br><br>";
+ }
+?>
+ <p>Please enter an algebraic expression <b>without</b> any surrounding @@ into
+ the text box below. (Click <a href="#help">here for help.</a>)
+ <form action="algebradebug.php" method="get"
+ target="inlineframe">
+ <center>
+ <input type="text" name="algebra" size=50
+ value="sin(z)/(x^2+y^2)">
+ </center>
+ <ol>
+ <li>First click on this button <input type="submit" name="ShowDB" value="Show DB Entry">
+ to see the cache_filters database entry for this expression.</li>
+ <li>If the database entry looks corrupt, click on this button to delete it:
+ <input type="submit" name="DeleteDB" value="Delete DB Entry"></li>
+ <li>Now click on this button <input type="submit" name="TeXStage1" value="First Stage Tex Translation">.
+ A preliminary translation into TeX will appear in the box below.</li>
+ <li>Next click on this button <input type="submit" name="TeXStage2" value="Second Stage Tex Translation">.
+ A more refined translation into TeX will appear in the box below.</li>
+ <li>Finally click on this button <input type="submit" name="ShowImage" value="Show Image">
+ to show a graphic image of the algebraic expression.</li>
+ </ol>
+ </form> <br> <br>
+ <center>
+ <iframe name="inlineframe" align="middle" width="80%" height="200">
+ &lt;p&gt;Something is wrong...&lt;/p&gt;
+ </iframe>
+ </center> <br>
+<hr>
+<a name="help">
+<h2>Debugging Help</h2>
+</a>
+<p>First here is a brief overview on how the algebra filter works. It
+takes an algebra expression and first translates it into TeX. It first
+looks for the TeX translation in the Moodle database in the table cache_filters
+in the field rawtext. If not found, it passes the algebraic expression to the
+Perl script algebra2tex.pl, which also uses the Perl library AlgParser.pm.
+It then saves the TeX translation in the database for subsequent uses and
+passes the TeX to the mimetex executable to be converted to a gif image.
+Here are a few common things that can go wrong and some suggestions on how
+you might try to fix them.</p>
+<ol>
+<li>Something had gone wrong on a previous occasion when the filter tried to
+translate this expression. Then the database entry for that expression contains
+a bad TeX translation in the rawtext field (usually blank). You can fix this
+by clicking on &quot;Delete DB Entry&quot;</li>
+<li>The First Stage TeX Translation gives a &quot;No text output available&quot;
+message. If your server is running Windows, this may be due to the fact that
+you haven't installed Perl or didn't install it correctly. If your server is
+running some version of Unix (e.g. Linux), then this may be due to your Perl
+binary being installed in a nonstandard location. To fix this edit the first
+line of the algebra2tex.pl script. Another possible problem which may affect
+both Unix and Windows servers is that the web server doesn't have execute permission
+on the algebra2tex.pl script. In that case change permissions accordingly</li>
+<li>The Second Stage TeX Translation produces malformed TeX. This indicates
+a bug in the algebra filter. Post the original algebraic expression and the
+bad TeX translation in the <a href="http://moodle.org/mod/forum/view.php?id=752">
+Mathematics Tools</a> forum in the Using Moodle course on moodle.org.</li>
+<li>The TeX to gif image conversion process does not work. If your server is
+running Unix, a likely cause is that the mimetex binary you are using is
+incompatible with your operating system. You can try compiling it from the
+C sources downloaded from <a href="http://www.forkosh.com/mimetex.zip">
+http://www.forkosh.com/mimetex.zip</a>, or looking for an appropriate
+binary at <a href="http://moodle.org/download/mimetex/">
+http://moodle.org/download/mimetex/</a>. You may then also need to
+edit your moodle/filter/algebra/pix.php file to add
+<br /><?PHP echo "case &quot;" . PHP_OS . "&quot;:" ;?><br ?> to the list of operating systems
+in the switch (PHP_OS) statement. Windows users may have a problem properly
+unzipping mimetex.exe. Make sure that mimetex.exe is is <b>PRECISELY</b>
+328192 bytes in size. If not, download fresh copy from
+<a href="http://moodle.org/download/mimetex/windows/mimetex.exe">
+http://moodle.org/download/mimetex/windows/mimetex.exe</a>. Lastly check
+the execute permissions on your mimetex binary, as outlined in item 2 above.</li>
+</ol>
+</body>
+</html>
@@ -172,7 +172,6 @@ function algebra_filter ($courseid, $text) {
$texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp);
$texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp);
$texexp = preg_replace('/\\\mbox{abs}\\\left\((.+?)\\\right\)/s',"|\$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);

0 comments on commit 9b361d2

Please sign in to comment.