# [LON-CAPA-dev] formularesponse with maxima: Addition issues?

**Gerd Kortemeyer
**
lon-capa-dev@mail.lon-capa.org

*Wed, 20 Jun 2007 08:11:43 -0400*

Hi,
Yes, there was a rather stupid bug. You can change lonmaxima.pm by
hand for now (see the diff below):
Modified files:
/loncom/homework lonmaxima.pm
Log:
- need parentheses
Index: loncom/homework/lonmaxima.pm
diff -u loncom/homework/lonmaxima.pm:1.15 loncom/homework/
lonmaxima.pm:1.16
--- loncom/homework/lonmaxima.pm:1.15 Tue May 29 16:56:39 2007
+++ loncom/homework/lonmaxima.pm Fri Jun 15 17:49:50 2007
@@ -1,7 +1,7 @@
# The LearningOnline Network with CAPA
# Interface routines to MAXIMA CAS
#
-# $Id: lonmaxima.pm,v 1.15 2007/05/29 20:56:39 albertel Exp $
+# $Id: lonmaxima.pm,v 1.16 2007/06/15 21:49:50 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -121,7 +121,7 @@
sub compareterms {
my ($socket,$terma,$termb)=@_;
- my $difference=$terma.'-'.$termb;
+ my $difference=$terma.'-('.$termb.')';
if (&blacklisted($difference)) { return 'Error: blacklisted'; }
my $reply=&maximareply($socket,'trigsimp(trigreduce('.
$difference.'));');
if ($reply=~/^\s*0\s*$/) { return 'true'; }
- Gerd.
On Jun 20, 2007, at 7:08 AM, Stefan Bisitz wrote:
>* Hi,
*>*
*>* Before starting a new bugreport, I'd like to ask if someone knows any
*>* issues with formularesponse with maxima using addition?!?
*>*
*>* It seems that LON-CAPA/Maxima doesn't accept an answer which contains
*>* additions. For example, use the "Formula Response using Computer
*>* Algebra
*>* System" template and add "+5" or "+x" to $derivative:
*>* --------
*>* <problem>
*>* <script type="loncapa/perl">
*>* $k=&random(3,6,1);
*>* $formula="a*x^$k";
*>* $m=$k-1;
*>* $derivative="$k*a*x^$m+x"; # original: $derivative="$k*a*x^$m";
*>* </script>
*>* <startouttext />
*>* What is the derivative of <tt>$formula</tt> with respect to x?
*>* <endouttext />
*>* <formularesponse answer="$derivative">
*>* <textline size="25" />
*>* </formularesponse>
*>* </problem>
*>* --------
*>*
*>>* From now on, LON-CAPA displays "ERROR:Computer's answer is
*>>* incorrect".
*>*
*>* Using mathresponse or formularesponse WITH sampling points, no
*>* problems
*>* could be seen.
*>*
*>* Any idea what's wrong?
*>*
*>* Stefan Bisitz
*>*
*>* _______________________________________________
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*>* LON-CAPA-dev@mail.lon-capa.org
*>* http://mail.lon-capa.org/mailman/listinfo/lon-capa-dev
*