--- loncom/homework/functionplotresponse.pm	2011/10/13 01:54:12	1.65
+++ loncom/homework/functionplotresponse.pm	2011/10/19 13:21:51	1.68
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: functionplotresponse.pm,v 1.65 2011/10/13 01:54:12 www Exp $
+# $Id: functionplotresponse.pm,v 1.68 2011/10/19 13:21:51 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -164,6 +164,14 @@ sub update_register {
 sub set_point_coordinate {
    my ($id,$variable,$x,$y,$fixed)=@_;
    my $mult=($fixed?'a*':'');
+# Get rid of wild exponents, make sure it's a number
+   $x=1.*$x;
+   $y=1.*$y;
+# GeoGebra does not understand "E"
+   $x=~s/[e|E]/\*10\^/;
+   $x=~s/\+//;
+   $y=~s/[e|E]/\*10\^/;
+   $y=~s/\+//;
    return (<<ENDSETVARIABLE);
 document.ggbApplet_$id.evalCommand("a=1");
 document.ggbApplet_$id.evalCommand("$variable=$mult($x,$y)");
@@ -973,6 +981,7 @@ sub compare_rel {
 
 sub addlog {
    my ($text)=@_;
+   $text=~s/\'/\\\'/g;
    $Apache::functionplotresponse::ruleslog.=$text.'<br />';
 }
 
@@ -981,6 +990,13 @@ sub actualval {
    return $xmin+$i/400.*($xmax-$xmin);
 }
 
+sub fpr_val {
+   my ($arg)=@_;
+   return &actualval($Apache::functionplotresponse::functionplotrulelabels{$arg},
+                     $Apache::functionplotresponse::fpr_xmin,
+                     $Apache::functionplotresponse::fpr_xmax);
+}
+
 sub fpr_f {
    my ($arg)=@_;
    return $Apache::functionplotresponse::func[&array_index($Apache::functionplotresponse::fpr_xmin,