--- loncom/interface/loncoursedata.pm	2003/03/27 19:29:36	1.63
+++ loncom/interface/loncoursedata.pm	2003/04/01 16:53:50	1.66
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: loncoursedata.pm,v 1.63 2003/03/27 19:29:36 matthew Exp $
+# $Id: loncoursedata.pm,v 1.66 2003/04/01 16:53:50 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -104,7 +104,7 @@ sub get_sequence_assessment_data {
     my $fn=$ENV{'request.course.fn'};
     ##
     ## use navmaps
-    my $navmap = Apache::lonnavmaps::navmap->new(Apache->request,$fn.".db",
+    my $navmap = Apache::lonnavmaps::navmap->new($fn.".db",
                                                  $fn."_parms.db",1,0);
     if (!defined($navmap)) {
         return 'Can not open Coursemap';
@@ -1150,6 +1150,47 @@ the students you are concerned with prio
 
 Inputs: $students, $symb, $part, $courseid
 
+=over 4
+
+=item $students is an array of hash references.  
+Each hash must contain at least the 'username' and 'domain' of a student.
+
+=item $symb is the symb for the problem.
+
+=item $part is the part id you need statistics for
+
+=item $courseid is the course id, of course!
+
+=back
+
+Outputs: See the code for up to date information.  A hash reference is
+returned.  The hash has the following keys defined:
+
+=over 4
+
+=item num_students The number of students attempting the problem
+      
+=item tries The total number of tries for the students
+      
+=item max_tries The maximum number of tries taken
+      
+=item mean_tries The average number of tries
+      
+=item num_solved The number of students able to solve the problem
+      
+=item num_override The number of students whose answer is 'correct_by_override'
+      
+=item deg_of_diff The degree of difficulty of the problem
+      
+=item std_tries The standard deviation of the number of tries
+      
+=item skew_tries The skew of the number of tries
+
+=item per_wrong The number of students attempting the problem who were not
+able to answer it correctly.
+
+=back
+
 =cut
 
 ################################################
@@ -1182,6 +1223,14 @@ sub get_problem_statistics {
         'CREATE TEMPORARY TABLE '.$stats_table.
             ' SELECT student_id,solved,award,tries FROM '.$performance_table.
                 ' WHERE symb_id='.$symb_id.' AND part_id='.$part_id;
+    if (defined($students)) {
+        $request .= ' AND ('.
+            join(' OR ', map {'student_id='.
+                                  &get_student_id($_->{'username'},
+                                                  $_->{'domain'})
+                                  } @$students
+                 ).')';
+    }
 #    &Apache::lonnet::logthis($request);
     $dbh->do($request);
     my ($num,$tries,$mod,$mean,$STD) = &execute_SQL_request
@@ -1202,17 +1251,28 @@ sub get_problem_statistics {
     $solved = 0 if (! defined($solved));
     #
     my $DegOfDiff = 'nan';
-    $DegOfDiff = 1-($Solved + $solved)/$tries if ($tries>0);
+    $DegOfDiff = 1-($Solved)/$tries if ($tries>0);
 
     my $SKEW = 'nan';
+    my $wrongpercent = 0;
     if ($num > 0) {
         ($SKEW) = &execute_SQL_request($dbh,'SELECT SQRT(SUM('.
                                      'POWER(tries - '.$STD.',3)'.
                                      '))/'.$num.' FROM '.$stats_table);
+        $wrongpercent=int(10*100*($num-$Solved+$solved)/$num)/10;
     }
     #
     $dbh->do('DROP TABLE '.$stats_table);  # May return an error
-    return ($num,$tries,$mod,$mean,$Solved,$solved,$DegOfDiff,$STD,$SKEW);
+    return { num_students => $num,
+             tries        => $tries,
+             max_tries    => $mod,
+             mean_tries   => $mean,
+             std_tries    => $STD,
+             skew_tries   => $SKEW,
+             num_solved   => $Solved,
+             num_override => $solved,
+             per_wrong    => $wrongpercent,
+             deg_of_diff  => $DegOfDiff }
 }
 
 sub execute_SQL_request {