--- loncom/homework/response.pm	2006/12/04 21:23:01	1.152
+++ loncom/homework/response.pm	2006/12/15 22:11:43	1.156
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.152 2006/12/04 21:23:01 albertel Exp $
+# $Id: response.pm,v 1.156 2006/12/15 22:11:43 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,6 +30,7 @@ package Apache::response;
 use strict;
 use Apache::lonlocal;
 use Apache::lonnet;
+use Apache::lonmaxima();
 
 BEGIN {
     &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse','customresponse','mathresponse'));
@@ -474,15 +475,13 @@ sub start_mathresponse {
 					   'cas',
 					   ['maxima'],
 					   $token);
-	$result.=&Apache::edit::text_arg('Algebra System:',
-					 'cas',$token);
 	$result.=&Apache::edit::text_arg('Argument Array:',
 					 'args',$token);
 	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
     } elsif ($target eq 'modified') {
 	my $constructtag;
 	$constructtag=&Apache::edit::get_new_args($token,$parstack,
-						  $safeeval,'answerdisplay');
+						  $safeeval,'answerdisplay','cas','args');
 	if ($constructtag) {
 	    $result = &Apache::edit::rebuild_tag($token);
 	    $result.=&Apache::edit::handle_insert();
@@ -511,10 +510,12 @@ sub end_mathresponse {
 	    $Apache::lonhomework::results{"resource.$part.$id.submission"}=
 		$response;
 	    my $error;
-	    ${$safeeval->varglob('LONCAPA::mathresponse_submission')}=
-		$response;
-	    
-	    my $award = &Apache::run::run('{ my $submission=$LONCAPA::mathresponse_submission;'.$Apache::response::custom_answer.'}',$safeeval);
+	    my $award;
+	    my $cas = &Apache::lonxml::get_param('cas',$parstack,$safeeval);
+            if ($cas eq 'maxima') {
+                my $args = [&Apache::lonxml::get_param_var('args',$parstack,$safeeval)];
+                $award=&Apache::lonmaxima::maxima_run($Apache::response::custom_answer,$response,$args);
+            }
 	    if (!&Apache::inputtags::valid_award($award)) {
 		$error = $award;
 		$award = 'ERROR';
@@ -534,6 +535,28 @@ sub end_mathresponse {
     return $result;
 }
 
+sub implicit_multiplication {
+    my ($expression)=@_;
+# Escape scientific notation, so 3e8 does not become 3*e*8
+# 3e8 -> 3&8; 3e-8 -> 3&-8; 3E+8 -> e&+8
+    $expression=~s/(\d+)e([\+\-]*\d+)/$1\&\($2\)/gsi;
+# 3x10^8 -> 3&8; 3*10^-8 -> 3&-8
+    $expression=~s/(\d+)(?:x|\*)10(?:\^|\*\*)([\+\-]*\d+)/$1\&\($2\)/gsi;
+# Fill in multiplication signs
+# a b -> a*b;3 b -> 3*b;3 4 -> 3*4
+    $expression=~s/(\w)\s+(\w)/$1\*$2/gs;
+# )( -> )*(; ) ( -> )*(
+    $expression=~s/\)\s*\(/\)\*\(/gs;
+# 3a -> 3*a; 3( -> 3*(; 3 ( -> 3*(; 3A -> 3*A
+    $expression=~s/(\d)\s*([a-zA-Z\(])/$1\*$2/gs;
+# a ( -> a*(
+    $expression=~s/(\w)\s+\(/$1\*\(/gs;
+# )a -> )*a; )3 -> )*3; ) 3 -> )*3
+    $expression=~s/\)\s*(\w)/\)\*$1/gs;
+# 3&8 -> 3e8; 3&-4 -> 3e-4
+    $expression=~s/(\d+)\&\(([\+\-]*\d+)\)/$1e$2/gs;
+    return $expression;
+}
 
 sub start_answer {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;