--- loncom/homework/functionplotresponse.pm	2011/11/21 20:20:48	1.82
+++ loncom/homework/functionplotresponse.pm	2011/11/21 21:45:32	1.84
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # Functionplot responses
 #
-# $Id: functionplotresponse.pm,v 1.82 2011/11/21 20:20:48 www Exp $
+# $Id: functionplotresponse.pm,v 1.84 2011/11/21 21:45:32 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -837,11 +837,11 @@ sub start_functionplotvectorrule {
              &Apache::edit::text_arg('Tip not attached to object:','nottippoint',
                                       $token,'16').'<br />'.
              &Apache::edit::text_arg('Length:','length',
-                                     $token,'16').
-             &Apache::edit::text_arg('Angle:','angle',
-                                     $token,'16').
+                                     $token,'30').
              &Apache::edit::text_arg('Absolute error length:','lengtherror',
-                                     $token,'8').
+                                     $token,'8').'<br />'.
+             &Apache::edit::text_arg('Angle:','angle',
+                                     $token,'30').
              &Apache::edit::text_arg('Absolute error angle:','angleerror',
                                      $token,'8').
              &Apache::edit::end_row();
@@ -912,12 +912,12 @@ sub start_functionplotvectorsumrule {
              &Apache::edit::text_arg('Comma-separated list of vectors:','vectors',
                                       $token,'30').'<br />'.
              &Apache::edit::text_arg('Sum vector length:','length',
-                                     $token,'16').
+                                     $token,'30').
+             &Apache::edit::text_arg('Absolute error length:','lengtherror',
+                                     $token,'8').'<br />'.
              &Apache::edit::text_arg('Sum vector angle:','angle',
-                                     $token,'16').
-             &Apache::edit::text_arg('Error length:','lengtherror',
-                                     $token,'8').
-             &Apache::edit::text_arg('Error angle:','angleerror',
+                                     $token,'30').
+             &Apache::edit::text_arg('Absolute error angle:','angleerror',
                                      $token,'8').
              &Apache::edit::end_row();
   } elsif ($target eq 'modified') {
@@ -1356,6 +1356,43 @@ sub fpr_d2fdx2 {
                                                                 $arg)];
 }
 
+sub fpr_vectorcoords {
+   my ($arg)=@_;
+   $arg=~s/\W//gs;
+   $arg=ucfirst($arg);
+   my $id=$Apache::inputtags::response[-1];
+   my $partid=$Apache::inputtags::part;
+   my $internalid = $partid.'_'.$id;
+   return ($env{'form.HWVAL_'.$internalid.'_'.$arg.'Start_x'},
+           $env{'form.HWVAL_'.$internalid.'_'.$arg.'End_x'},
+           $env{'form.HWVAL_'.$internalid.'_'.$arg.'Start_y'},
+           $env{'form.HWVAL_'.$internalid.'_'.$arg.'End_y'});
+}
+
+sub fpr_objectcoords {
+   my ($arg)=@_;
+   $arg=~s/\W//gs;
+   $arg=ucfirst($arg);
+   my $id=$Apache::inputtags::response[-1];
+   my $partid=$Apache::inputtags::part;
+   my $internalid = $partid.'_'.$id;
+   return ($env{'form.HWVAL_'.$internalid.'_'.$arg.'_x'},
+           $env{'form.HWVAL_'.$internalid.'_'.$arg.'_y'});
+}
+
+sub fpr_vectorlength {
+   my ($arg)=@_;
+   my ($xs,$xe,$ys,$ye)=&fpr_vectorcoords($arg);
+   return sqrt(($xe-$xs)*($xe-$xs)+($ye-$ys)*($ye-$ys));
+}
+
+sub fpr_vectorangle {
+   my ($arg)=@_;
+   my ($xs,$xe,$ys,$ye)=&fpr_vectorcoords($arg);
+   my $angle=57.2957795*atan2(($ye-$ys),($xe-$xs));
+   if ($angle<0) { $angle=360+$angle; }
+   return $angle;
+}
 
 sub vectorcoords {
    my ($id,$label)=@_;
@@ -1528,6 +1565,34 @@ sub sumcheck {
       $sumy+=$ry;
    }
    &addlog("Sum vector ($sumx,$sumy)");
+   if ($length ne '') {
+      &addlog("Checking length $length with error $lengtherror");
+      $length=&Apache::run::run($length,$safeeval);
+      &addlog("Evaluated to $length");
+      my $thislength=&vectorlength($sumx,$sumy);
+      &addlog("Actual length $thislength");
+      if (abs($length-$thislength)>$lengtherror) {
+                  &setfailed($label);
+         return 0;
+      }
+   }
+   if ($angle ne '') {
+      &addlog("Checking angle $angle with error $angleerror");
+      $angle=&Apache::run::run($angle,$safeeval);
+      &addlog("Evaluated to $angle");
+      my $thisangle=&vectorangle($sumx,$sumy);
+      &addlog("Actual 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;
 }