--- loncom/homework/functionplotresponse.pm	2011/11/20 02:53:27	1.79
+++ loncom/homework/functionplotresponse.pm	2011/11/21 02:34:58	1.80
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # Functionplot responses
 #
-# $Id: functionplotresponse.pm,v 1.79 2011/11/20 02:53:27 www Exp $
+# $Id: functionplotresponse.pm,v 1.80 2011/11/21 02:34:58 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -914,8 +914,7 @@ sub start_functionplotvectorsumrule {
            $object,
            &Apache::lonxml::get_param('length',$parstack,$safeeval),
            &Apache::lonxml::get_param('angle',$parstack,$safeeval),
-           &Apache::lonxml::get_param('lengthpercenterror',$parstack,$safeeval),
-           &Apache::lonxml::get_param('lengthabserror',$parstack,$safeeval),
+           &Apache::lonxml::get_param('lengtherror',$parstack,$safeeval),
            &Apache::lonxml::get_param('angleerror',$parstack,$safeeval),
           )));
    } elsif ($target eq 'edit') {
@@ -928,9 +927,7 @@ sub start_functionplotvectorsumrule {
                                      $token,'16').
              &Apache::edit::text_arg('Sum vector angle:','angle',
                                      $token,'16').
-             &Apache::edit::text_arg('Percent error length:','lengthpercenterror',
-                                     $token,'8').
-             &Apache::edit::text_arg('Absolute error length:','lengthabserror',
+             &Apache::edit::text_arg('Error length:','lengtherror',
                                      $token,'8').
              &Apache::edit::text_arg('Error angle:','angleerror',
                                      $token,'8').
@@ -940,7 +937,7 @@ sub start_functionplotvectorsumrule {
     my $constructtag=&Apache::edit::get_new_args($token,$parstack,
                                                  $safeeval,'index','object',
                                                            'length','angle',
-                                                           'lengthpercenterror','lengthabserror','angleerror');
+                                                           ,'lengtherror','angleerror');
     if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
    }
    return $result;
@@ -1445,13 +1442,30 @@ sub vectorcheck {
          return 0;
       }
    }
+   if ($angle ne '') {
+      &addlog("Checking for angle $angle with error $angleerror");
+      $angle=&Apache::run::run($angle,$safeeval);
+      &addlog("Angle evaluated to $angle");
+      my $thisangle=&plotvectorangle($id,$vector);
+      &addlog("Found angle $thisangle");
+      my $anglediff=abs($thisangle-$angle);
+      &addlog("Angle difference: $anglediff");
+      if ($anglediff>360.-$anglediff) {
+         $anglediff=360.-$anglediff;
+      }
+      &addlog("Smallest angle difference: $anglediff");
+      if ($anglediff>$angleerror) {
+         &setfailed($label);
+         return 0;
+      }
+   }
    &addlog("Rule $label passed.");
    return 1;
 }
 
 sub sumcheck {
    my ($rule,$xmin,$xmax,$ymin,$ymax,$safeeval)=@_;
-   my ($label,$type,$id,$object,$length,$angle,$lengthpercenterror,$lengthabserror,$angleerror)=split(/\:/,$rule);
+   my ($label,$type,$id,$object,$length,$angle,$lengtherror,$angleerror)=split(/\:/,$rule);
    &addlog("Vector Sum Rule $label for vectors attached to ".$object);
 
    &addlog("Rule $label passed.");