--- loncom/xml/lontexconvert.pm	2005/02/24 01:21:50	1.44
+++ loncom/xml/lontexconvert.pm	2005/02/24 09:54:01	1.55
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.44 2005/02/24 01:21:50 albertel Exp $
+# $Id: lontexconvert.pm,v 1.55 2005/02/24 09:54:01 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -213,15 +213,19 @@ sub msgtexconverted {
 }
 
 sub algebra {
+    use AlgParser;
+
     my ($string,$target)=@_;
     my $parser = new AlgParserWithImplicitExpand;
+    $string=&prepare_algebra($string);
     my $ret = $parser->parse($string);
     my $result='['.&mt('Algebra unconverted due to previous errors').']';
     if ( ref($ret) ) {
-	$parser->tostring();
+	#$parser->tostring();
 	$parser->normalize();
 	my $latex=$parser->tolatex();
-	$latex='$$'.$latex.'$$';
+	$latex=&postprocess_algebra($latex);
+	$latex='$'.$latex.'$';
 	if ($target eq 'web' || $target eq 'analyze') {
 	    $result = &converted(\$latex);
 	} else {
@@ -232,6 +236,46 @@ sub algebra {
     }
 }
 
+sub prepare_algebra {
+    my ($string)=@_;
+
+    # makes the decision about what is a minus sign easier supposedly
+    $string =~ s/([\=\>\<\%\!\#] *)-/$1 zeroplace -/g;
+
+    return $string;
+}
+
+sub postprocess_algebra {
+    my ($string)=@_;
+    
+    # moodle had these and I don't know why, ignoring them for now
+    # $string =~s/\\fun/ /g;
+
+    # sqrt(3,4) -> \sqrt\let{3,4\right}, which is annoying
+    $string =~s/\\left\{/\{/g;
+    $string =~s/\\right\}/\}/g;
+
+    # remove the extra () in the denominator of a \frac
+    $string =~s/\\frac{(.+?)}{\\left\((.+?)\\right\)}/\\frac{$1}{$2}/gs;
+    
+    # sqrt(3,4) means the 4 root of 3
+    $string =~s/\\sqrt{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
+
+    # log(3,4) means the log base 4 of 3
+    $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;
+
+    # log(3,4) means the log base 4 of 3
+    $string =~s/\\((?:sin|cos|tan|sec|csc|cot)(?:h)?)\\left\((.+?),(.+?)\\right\)/\\$1^{$3}\\left($2\\right)/gs;
+
+    # int(3,a,b) integral from a to b of 3
+    $string =~s/\\int\\left\((.+?),(.+?),(.+?)\\right\)/\\int_{$2}^{$3}\\left($1\\right)/gs;
+
+    # int( ... dx) -> ...
+    $string =~s/\\int\\left\((.+?)d[a-z]\\right\)/$1/gs;
+
+    &Apache::lonnet::logthis($string);
+    return $string;
+}
 1;
 __END__