--- loncom/homework/functionplotresponse.pm	2010/11/09 02:29:52	1.30
+++ loncom/homework/functionplotresponse.pm	2010/11/10 22:53:32	1.32
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: functionplotresponse.pm,v 1.30 2010/11/09 02:29:52 www Exp $
+# $Id: functionplotresponse.pm,v 1.32 2010/11/10 22:53:32 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -398,17 +398,17 @@ sub start_functionplotrule {
              &Apache::edit::select_arg(&mt('Function:'),'derivative',
                                   [['0','Function itself'],
                                    ['1','First derivative'],
-                                   ['2','Second derivative']],$token).' '.
+                                   ['2','Second derivative']],$token).'<br />'.
 
              &Apache::edit::text_arg('(Initial) x-value:','xinitial',
                                       $token,'4').
              &Apache::edit::select_or_text_arg('(Initial) x-value label:','xinitiallabel',
-                                               [['start','Start of Plot']],$token,'8').'&nbsp;'.
+                                               [['start','Start of Plot']],$token,'8').'<br />'.
 
              &Apache::edit::text_arg('Optional final x-value for ranges:','xfinal',
                                       $token,'4').
              &Apache::edit::select_or_text_arg('Optional final x-value label:','xfinallabel',
-                                               [['end','End of Plot']],$token,'8').'&nbsp;'.
+                                               [['end','End of Plot']],$token,'8').'<br />'.
 
              &Apache::edit::select_arg(&mt('Relationship:'),'relationship',
                                   [['eq','equal'],
@@ -719,7 +719,7 @@ sub start_functionplotresponse {
              &Apache::edit::text_arg('Maximum x-value:','xmax',
                                      $token,'4').'&nbsp;'.
              &Apache::edit::select_arg('x-axis visible:','xaxisvisible',
-                                  ['yes','no'],$token).'&nbsp;&nbsp;'.
+                                  ['yes','no'],$token).'<br />'.
              &Apache::edit::text_arg('Label y-axis:','ylabel',
                                      $token,'6').'&nbsp;'.
              &Apache::edit::text_arg('Minimum y-value:','ymin',
@@ -727,7 +727,7 @@ sub start_functionplotresponse {
              &Apache::edit::text_arg('Maximum y-value:','ymax',
                                      $token,'4').'&nbsp;'.
              &Apache::edit::select_arg('y-axis visible:','yaxisvisible',
-                                  ['yes','no'],$token).'&nbsp;&nbsp;'.
+                                  ['yes','no'],$token).'<br />'.
              &Apache::edit::select_arg('Grid visible:','gridvisible',
                                   ['yes','no'],$token).
              &Apache::edit::end_row().&Apache::edit::start_spanning_row();
@@ -792,13 +792,24 @@ sub compare_rel {
 
 sub functionplotrulecheck {
    my ($rule,$xmin,$xmax,$tolfunc,$toldfdx,$told2fdx2)=@_;
-   &Apache::lonnet::logthis("Rule $rule TolFunc $tolfunc TolDfDx $toldfdx TolD2fDx2 $told2fdx2");
+#   &Apache::lonnet::logthis("Rule $rule TolFunc $tolfunc TolDfDx $toldfdx TolD2fDx2 $told2fdx2");
    my ($label,$derivative,$xinitial,$xinitiallabel,$xfinal,$xfinallabel,$relationship,$value)
       =split(/\:/,$rule);
 
    my $li=0;
    my $lh=400;
 
+# Special case: the upper boundary was not defined
+# and needs to be set to the value where
+# the condition is not true anymore => set flag
+
+   my $findupper=0;
+   if (($xfinal eq '')
+    && (!defined($Apache::functionplotresponse::functionplotrulelabels{$xfinallabel}))
+    && ($xfinallabel)) {
+       $findupper=1;
+   }
+
 # if a hard value is set for the boundaries, it overrides the label
    if (($xinitial ne '') && ($xinitiallabel ne '') && ($xinitiallabel ne 'start')) {
       $li=&array_index($xmin,$xmax,$xinitial);
@@ -808,15 +819,18 @@ sub functionplotrulecheck {
       $lh=&array_index($xmin,$xmax,$xfinal);
       $Apache::functionplotresponse::functionplotrulelabels{$xfinallabel}=$lh;
    }
+# if the label is defined, use it
    if (defined($Apache::functionplotresponse::functionplotrulelabels{$xinitiallabel})) {
       $li=$Apache::functionplotresponse::functionplotrulelabels{$xinitiallabel};
    } else {
       $li=&array_index($xmin,$xmax,$xinitial);
    }
-   if (defined($Apache::functionplotresponse::functionplotrulelabels{$xfinallabel})) {
-      $lh=$Apache::functionplotresponse::functionplotrulelabels{$xfinallabel};
-   } else {
-      $lh=&array_index($xmin,$xmax,$xfinal);
+   unless ($findupper) {
+      if (defined($Apache::functionplotresponse::functionplotrulelabels{$xfinallabel})) {
+         $lh=$Apache::functionplotresponse::functionplotrulelabels{$xfinallabel};
+      } else {
+         $lh=&array_index($xmin,$xmax,$xfinal);
+      }
    }
 # Basic sanity checks
    if ($li<0) { $li=0; }
@@ -824,7 +838,8 @@ sub functionplotrulecheck {
    if ($li>$lh) {
        $lh=$li;
    }
-   &Apache::lonnet::logthis("Init $xinitial=$li Final $xfinal=$lh");
+
+#   &Apache::lonnet::logthis("Init $xinitial=$li Final $xfinal=$lh Findupper: $findupper");
    my $tol=$tolfunc;
    if ($derivative==2) {
       $tol=$told2fdx2;
@@ -840,7 +855,16 @@ sub functionplotrulecheck {
         } else {
            $val=$Apache::functionplotresponse::func[$i];
         }
-        unless (&compare_rel($relationship,$value,$val,$tol)) { return 0; };
+        unless (&compare_rel($relationship,$value,$val,$tol)) { 
+#           &Apache::lonnet::logthis("Condition false $findupper at $i with $val");
+           if (($findupper) && ($i>$li)) {
+              $Apache::functionplotresponse::functionplotrulelabels{$xfinallabel}=$i;
+#              &Apache::lonnet::logthis("Setting $xfinallabel to $i");
+              return 1;
+           } else {
+              return 0; 
+           }
+        }
    }
    return 1;
 }