--- loncom/interface/statistics/lonproblemstatistics.pm	2002/08/13 13:57:25	1.21
+++ loncom/interface/statistics/lonproblemstatistics.pm	2002/08/14 13:13:37	1.24
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # (Publication Handler
 #
-# $Id: lonproblemstatistics.pm,v 1.21 2002/08/13 13:57:25 stredwic Exp $
+# $Id: lonproblemstatistics.pm,v 1.24 2002/08/14 13:13:37 stredwic Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -87,6 +87,19 @@ sub BuildProblemStatisticsPage {
 #    my %Discuss=&Apache::loncoursedata::LoadDiscussion($courseID);
 #    my ($upper, $lower) = &Discriminant(\%discriminant,$r);
     if(!defined($cache{'StatisticsCached'})) {
+        if(defined($cache{'StatisticsCached'})) {
+            untie(%cache);
+            unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
+                $r->print('Unable to tie database.');
+                return;
+            }
+            my @statkeys = split(':::', $cache{'StatisticsKeys'});
+            delete $cache{'StatisticsKeys'};
+            delete $cache{'StatisticsCached'};
+            foreach(@statkeys) {
+                delete $cache{$_};
+            }
+        }
         untie(%cache);
         &Apache::loncoursedata::DownloadStudentCourseDataSeparate($students,
                                                                   'true',
@@ -102,7 +115,7 @@ sub BuildProblemStatisticsPage {
             return;
         }
         my ($problemData) = &ExtractStudentData(\%cache, $students);
-        &CalculateStatistics($problemData);
+        &CalculateStatistics($problemData, \%cache);
         untie(%cache);
 
         unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
@@ -112,6 +125,7 @@ sub BuildProblemStatisticsPage {
         foreach(keys(%$problemData)) {
             $cache{$_} = $problemData->{$_};
         }
+        $cache{'StatisticsKeys'} = join(':::', keys(%$problemData));
         $cache{'StatisticsCached'} = 'true';
         untie(%cache);
 
@@ -130,6 +144,50 @@ sub BuildProblemStatisticsPage {
     return;
 }
 
+sub BuildGraphicChart {
+    my ($graph,$cacheDB,$courseDescription,$r)=@_;
+    my %cache;
+    my $max = 0;
+
+    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
+        return '<html><body>Unable to tie database.</body></html>';
+    }
+   
+    my @problems = split(':::', $cache{'problemList'});
+    my @values = ();
+    foreach (@problems) {
+        my $data = 0;
+        if($graph eq 'DoDiffGraph') {
+            $data = sprintf("%.2f", $cache{$_.':degreeOfDifficulty'}),
+        } else {
+            $data = sprintf("%.1f", $cache{$_.':percentWrong'}),
+        }
+        if($max < $data) {
+            $max = $data;
+        }
+        push(@values, $data);
+    }
+    untie(%cache);
+
+    my $sendValues = join(',', @values);
+#    my $sendCount = $#values;
+    my $sendCount = scalar(@values);
+
+    my $title = '';
+    if($graph eq 'DoDiffGraph') {
+	$title = 'Degree-of-Difficulty';
+    } else {
+	$title = 'Wrong-Percentage';
+    }
+    my @GData = ($courseDescription, 'Problems', $title, $max, $sendCount, 
+                 $sendValues);
+
+    $r->print('</form>'."\n");
+    $r->print('<IMG src="/cgi-bin/graph.gif?'.(join('&', @GData)).'" border="1" />');
+    $r->print('<form>'."\n");
+
+    return;
+}
 
 #---- Problem Statistics Web Page ---------------------------------------
 
@@ -178,11 +236,10 @@ sub BuildStatisticsTable {
     my $count = 1;
     foreach(@$orderedProblems) {
         my ($sequence,$problem,$part)=split(':', $_);
-#        if($cache->{'ProblemStatisticsMaps'} ne 'All Maps'  &&
-#           $cache->{'ProblemStatisticsMaps'} ne $cache->{$sequence.':title'}) {
-#            next;
-#        }
-
+        if($cache->{'ProblemStatisticsMaps'} ne 'All Maps'  &&
+           $cache->{'ProblemStatisticsMaps'} ne $cache->{$sequence.':title'}) {
+            next;
+        }
 
         my $ref = '<a href="'.$cache->{$problem.':source'}.
                   '" target="_blank">'.$cache->{$problem.':title'}.'</a>';
@@ -453,6 +510,32 @@ sub ExtractStudentData {
         }
     }
 
+    my @upperStudents1=();
+    my @lowerStudents1=();
+    my @upperStudents2=();
+    my @lowerStudents2=();
+    my $upperCount = int(0.27*scalar(@$students));
+    # Discriminant Factor criterion 1
+    my $sortedStudents = &SortDivideByTries($students,$cache,':totalAwarded');
+
+    for(my $i=0; $i<$upperCount; $i++) {
+        push(@lowerStudents1, $sortedStudents->[$i]);
+        push(@upperStudents1, $sortedStudents->[(scalar(@$students)-$i-1)]);
+    }
+
+    $problemData{'studentsUpperListCriterion1'}=join(':::', @upperStudents1);
+    $problemData{'studentsLowerListCriterion1'}=join(':::', @lowerStudents1);
+
+    # Discriminant Factor criterion 2
+    $sortedStudents = &SortDivideByTries($students, $cache, ':totalSolved');
+
+    for(my $i=0; $i<$upperCount; $i++) {
+        push(@lowerStudents2, $sortedStudents->[$i]);
+        push(@upperStudents2, $sortedStudents->[(scalar(@$students)-$i-1)]);
+    }
+    $problemData{'studentsUpperListCriterion2'}=join(':::', @upperStudents2);
+    $problemData{'studentsLowerListCriterion2'}=join(':::', @lowerStudents2);
+
     $problemData{'problemList'} = join(':::', @problemList);
 #                $Discussed=0;
 #                if($Discuss->{"$name:$problem"}) {
@@ -463,6 +546,18 @@ sub ExtractStudentData {
     return \%problemData;
 }
 
+sub SortDivideByTries {
+    my ($toSort, $data, $sortOn)=@_;
+    my @orderedData = sort { ($data->{$a.':totalTries'}) ? 
+                             ($data->{$a.$sortOn}/$data->{$a.':totalTries'}):0
+                             <=>
+                             ($data->{$b.':totalTries'}) ? 
+                             ($data->{$b.$sortOn}/$data->{$b.':totalTries'}):0
+                           } @$toSort;
+
+    return \@orderedData;
+}
+
 sub SortProblems {
     my ($problemData,$sortBy,$ascend)=@_;
 
@@ -499,7 +594,7 @@ sub SortProblems {
 }
 
 sub CalculateStatistics {
-    my ($data)=@_;
+    my ($data, $cache)=@_;
 
     my @problems = split(':::', $data->{'problemList'});
     foreach(@problems) {
@@ -543,136 +638,48 @@ sub CalculateStatistics {
              0;
 
         # Discrimination Factor 1
-        $data->{$_.':discriminationFactor1'} = 0;
+        my ($sequence, $problem, $part) = split(':', $_);
 
-        # Discrimination Factor 2
-        $data->{$_.':discriminationFactor2'} = 0;
-    }
+        my @upper1 = split(':::', $data->{'studentsUpperListCriterion1'});
+        my @lower1 = split(':::', $data->{'studentsLowerListCriterion1'});
 
-    return;
-}
-
-sub ProcessDiscriminant {
-    my ($List) = @_;
-    my @sortedList = sort (@$List);
-    my $Count = scalar @sortedList;
-    my $Problem;
-    my @Dis;
-    my $Slvd=0;
-    my $tmp;
-    my $Sum1=0;
-    my $Sum2=0;
-    my $nIndex=0;
-    my $nStudent=0;
-    my %Proc=undef;
-    while ($nIndex<$Count) {
-#        $jr->print("<br> $nIndex) $sortedList[$nIndex]");
-	($Problem,$tmp)=split(/\=/,$sortedList[$nIndex]);
-	@Dis=split(/\+/,$tmp);
-	my $Temp = $Problem;
-	do {
-	    $nIndex++;
-	    $nStudent++;
-	    $Sum1 += $Dis[0];
-	    $Sum2 += $Dis[1];
-	    ($Problem,$tmp)=split(/\=/,$sortedList[$nIndex]);
-	    @Dis=split(/\+/,$tmp);
-	} while ( $Problem eq $Temp && $nIndex < $Count );
-	$Proc{$Temp}=($Sum1/$nStudent).':'.($Sum2/$nStudent);
-#        $jr->print("<br> $nIndex) $Temp --> ($nStudent) $Proc{$Temp}");
-	$Sum1=0;
-	$Sum2=0;
-	$nStudent=0;
-    }
-
-    return %Proc;
-}
-
-#------- Creating Discimination factor   
-sub Discriminant {
-    my ($discriminant)=@_;
-    my @discriminantKeys=keys(%$discriminant);
-    my $Count = scalar @discriminantKeys;
-
-    my $UpCnt = int(0.27*$Count);
-    my $low=0;
-    my $up=$Count-$UpCnt;
-    my @UpList=();
-    my @LowList=();
-
-    $Count=0;
-    foreach my $key (sort(@discriminantKeys)) { 
-	$Count++;    
-	if($low < $UpCnt || $Count > $up) {
-            $low++;
-            my $str=$discriminant->{$key};
-            foreach(split(/\&/,$str)){
-                if($_) {
-                    if($low<$UpCnt) { push(@LowList,$_); }
-                    else            { push(@UpList,$_);  }
-                }
-            }
+        my $upper1Sum=0;
+        foreach my $name (@upper1) {
+            $upper1Sum += $cache->{"$name:$problem:$part:awarded"};
         }
-    }
-    my %DisUp =  &ProcessDiscriminant(\@UpList);
-    my %DisLow = &ProcessDiscriminant(\@LowList);
+        $upper1Sum /= (scalar(@upper1)) ? (scalar(@upper1)) : 0;
 
-    return (\%DisUp, \%DisLow);
-}   
-
-#---- END Problem Statistics Web Page ----------------------------------------
-
-#---- Problem Statistics Graph Web Page --------------------------------------
+        my $lower1Sum=0;
+        foreach my $name (@lower1) {
+            $lower1Sum += $cache->{"$name:$problem:$part:awarded"};
+        }
+        $lower1Sum /= (scalar(@lower1)) ? (scalar(@lower1)) : 0;
 
-# ------------------------------------------- Prepare data for Graphical chart
+        $data->{$_.':discriminationFactor1'} = $upper1Sum - $lower1Sum;
 
-sub BuildGraphicChart {
-    my ($ylab,$r,$cacheDB)=@_;
-    my %cache;
-    my $Col;
-    my $data='';
-    my $count = 0;
-    my $Max = 0;
+        # Discrimination Factor 2
+        my @upper2 = split(':::', $data->{'studentsUpperListCriterion2'});
+        my @lower2 = split(':::', $data->{'studentsLowerListCriterion2'});
 
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
-        return '<html><body>Unable to tie database.</body></html>';
-    }
-   
-    my $p_count = $cache{'ProblemCount'};
+        my $upper2Sum=0;
+        foreach my $name (@upper2) {
+            $upper2Sum += $cache->{"$name:$problem:$part:awarded"};
+        }
+        $upper2Sum /= (scalar(@upper2)) ? (scalar(@upper2)) : 0;
 
-    for ( my $k=0; $k<$p_count;$k++) {
-        my @Temp=split(/\:/,$cache{'GraphGif:'.$k});
-        my $inf = $Temp[$Col]; 
-	if ( $Max < $inf ) {$Max = $inf;}
-      	$data .= $inf.',';
-       	$count++;
-    }
-    untie(%cache);
-#    $r->print("<br>count=$p_count >>data= $data");
+        my $lower2Sum=0;
+        foreach my $name (@lower2) {
+            $lower2Sum += $cache->{"$name:$problem:$part:awarded"};
+        }
+        $lower2Sum /= (scalar(@lower2)) ? (scalar(@lower2)) : 0;
 
-    if ( $Max > 1 ) { 
-	$Max += (10 - $Max % 10);
-      	$Max = int($Max);
-    } else { $Max = 1; }
-
-    my $cid=$ENV{'request.course.id'};
-
-    if ( $ylab eq 'DoDiff Graph' ) {
-	$ylab = 'Degree-of-Difficulty';
-	$Col = 0;
-    } else {
-	$ylab = 'Wrong-Percentage';
-	$Col = 1;
+        $data->{$_.':discriminationFactor2'} = $upper2Sum - $lower2Sum;
     }
-    my $Course = $ENV{'course.'.$cid.'.description'};
-    $Course =~ s/\ /"_"/eg;
-    my $GData=$Course.'&'.'Problems#'.'&'.$ylab.'&'.
-	      $Max.'&'.$count.'&'.$data;
-
-    $r->print('<IMG src="/cgi-bin/graph.gif?'.$GData.'" />');
 
     return;
 }
 
+#---- END Problem Statistics Web Page ----------------------------------------
+
 1;
 __END__