--- loncom/interface/lonstatistics.pm	2002/07/17 12:53:00	1.27
+++ loncom/interface/lonstatistics.pm	2002/08/14 17:45:19	1.45
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # (Publication Handler
 #
-# $Id: lonstatistics.pm,v 1.27 2002/07/17 12:53:00 stredwic Exp $
+# $Id: lonstatistics.pm,v 1.45 2002/08/14 17:45:19 stredwic Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -31,1264 +31,25 @@
 # 11/1,11/4,11/16,12/14,12/16,12/18,12/20,12/31 Behrouz Minaei
 # YEAR=2002
 # 1/22,2/1,2/6,2/25,3/2,3/6,3/17,3/21,3/22,3/26,4/7,5/6 Behrouz Minaei
-# 5/12,5/14,5/15,5/19,5/26 Behrouz Minaei
+# 5/12,5/14,5/15,5/19,5/26,7/16,25/7,29/7  Behrouz Minaei
 #
 ###
 
 package Apache::lonstatistics; 
 
-use strict; 
+use strict;
 use Apache::Constants qw(:common :http);
 use Apache::lonnet();
 use Apache::lonhomework;
 use Apache::loncommon;
 use Apache::loncoursedata;
+use Apache::lonhtmlcommon;
+use Apache::lonproblemanalysis;
+use Apache::lonproblemstatistics;
+use Apache::lonstudentassessment;
 use HTML::TokeParser;
 use GDBM_File;
 
-# -------------------------------------------------------------- Module Globals
-my %hash;
-my %CachData;
-my %GraphDat;
-my %mapsort;
-my $Pos;
-my $r;
-my $GData;
-my %color;
-my %foil_to_concept;
-my @Concepts;
-my %ConceptData;
-my %Answer = ();
-
-sub Activity {
-    my $file="/home/minaeibi/activity.log";
-    my $userid='adamsde1';
-    $r->print("<br>Using $file");
-    $r->rflush();
-    open(FILEID, "<$file");
-    my $line;
-    my @allaccess;
-    my $Count=0;
-    while ($line=<FILEID>) {
-	my ($time,$machine,$what)=split(':',$line);
-	$what=&Apache::lonnet::unescape($what);
-	my @accesses=split('&',$what);
-	foreach my $access (@accesses) {
-	    my ($date,$resource,$who,$domain,$post,@posts)=split(':',$access);
-	    if ($who ne $userid) { next; }
-	    if (!$resource) { next; }
-	    my $res=&Apache::lonnet::unescape($resource);
-	    if (($res =~ /\.(problem|htm|html)/)) {
-		$Count++;
-		$r->print("<br>$Count) ".localtime($date).": $who --> $res");
-#	        if ($post) { 
-#		    $Count++;
-#		    $r->print("<br><b>$Count) Sent data ".join(':',
-#                              &Apache::lonnet::unescape(@posts)).'</b>');
-#		}
-		$r->rflush();
-	    }
-	##    push (@allaccess,unescape($access));
-	    #print $machine;
-	}
-    }
-#    @allaccess=sort(@allaccess);
-#    $Count=0;
-#    foreach my $access (@allaccess) {
-#	my ($date,$resource,$who,$domain,$post,@posts)=split(':',$access);
-#	$Count++;
-#	$r->print("<br>$Count) $date: $who --> $resource");
-#	$r->rflush();
-#	if ($post) { 
-#	    $r->print("<br><b>Sent data ".join(':',unescape(@posts)).'</b>');
-#	}
-#    }
-}
-
-#---- Analyze Web Page ---------------------------------------------------
-
-sub InitAnalysis {
-    my ($uri,$part,$problem,$student,$courseID)=@_;
-    my ($username,$userdomain)=split(/\:/,$student);
-
-    # Render the student's view of the problem.  $Answ is the problem 
-    # Stringafied
-    my $Answ=&Apache::lonnet::ssi($uri,('grade_target'   => 'analyze',
-                                        'grade_username' => $username,
-                                        'grade_domain'   => $userdomain,
-                                        'grade_courseid' => $courseID,
-                                        'grade_symb'     => $problem));
-#    my $Answ=&Apache::lonnet::ssi($uri,('grade_target' => 'analyze'));
-
-#    (undef,$Answ)=split(/_HASH_REF__/,$Answ,2);
-    %Answer=();
-    %Answer=&Apache::lonnet::str2hash($Answ);
-
-#    foreach (sort(keys(%Answer))) {
-#        $r->print($_.'  '.$Answer{$_}.'<br>');
-#    }
-
-    my $parts='';
-    foreach my $elm (@{$Answer{"parts"}}) {
-	$parts.="$elm,";
-    }
-    chop($parts);
-    my $conc='';
-    foreach my $elm (@{$Answer{"$parts.concepts"}}) {
-	$conc.="$elm@";
-    }
-    chop($conc);
-
-    @Concepts=split(/\@/,$conc);
-    foreach my $concept (@{$Answer{"$parts.concepts"}}) {
-	foreach my $foil (@{$Answer{"$parts.concept.$concept"}}) {
-	    $foil_to_concept{$foil} = $concept;
-	    #$ConceptData{$foil} = $Answer{"$parts.foil.value.$foil"};
-	}
-    }
-
-    return;
-}
-
-sub Interval {
-    my ($part,$symb)=@_;
-    my $interval=$ConceptData{"Interval"};
-    my $due  = &Apache::lonnet::EXT('resource.'.$part.'.duedate',$symb)+1;
-    my $open = &Apache::lonnet::EXT('resource.'.$part.'.opendate',$symb);
-    my $add=int(($due-$open)/$interval);
-    $ConceptData{'Interval.0'}=$open;
-    for (my $i=1;$i<$interval;$i++) {
-	$ConceptData{'Interval.'.$i}=$open+$i*$add;
-    }
-    $ConceptData{'Interval.'.$interval}=$due;     
-    for (my $i=0;$i<$interval;$i++) {
-	for (my $n=0; $n<=$#Concepts; $n++ ) {
-	    my $tmp=$Concepts[$n];
-	    $ConceptData{$tmp.'.'.$i.'.true'}=0;
-	    $ConceptData{$tmp.'.'.$i.'.false'}=0;
-	}
-    }
-}
-
-sub ShowOpGraph {
-    my ($cache, $students, $courseID)=@_;
-    my $uri      = $cache->{'AnalyzeURI'};
-    my $part     = $cache->{'AnalyzePart'};
-    my $problem  = $cache->{'AnalyzeProblem'};
-    my $title    = $cache->{'AnalyzeProblem'};
-    my $interval = $cache->{'Interval'};
-    $ConceptData{"Interval"} = $interval;
-
-    #Initialize the option response true answers
-    &InitAnalysis($uri, $part, $problem, $students->[0],$courseID);
-
-    #compute the intervals
-    &Interval($part,$problem);
-
-    $title =~ s/\ /"_"/eg;
-    $r->print('<br><b>'.$uri.'</b>');
-    $r->rflush();
-    
-    #Java script Progress window
-    &Create_PrgWin();
-    &Update_PrgWin("Starting to analyze problem",0,0,'');
-    for(my $index=0; $index<(scalar @$students); $index++) {
-	&Update_PrgWin(scalar @$students, $index+1, $students->[$index]);
-	&OpStatus($problem, $students->[$index], $courseID);
-    }
-    &Close_PrgWin();
-
-    $r->print('<br>');
-    for(my $k=0; $k<$interval; $k++ ) {
-	&DrawGraph($k,$title);
-    }
-    for(my $k=0; $k<$interval; $k++ ) {
-	&DrawTable($k);
-    }
-#$Apache::lonxml::debug=1;
-#&Apache::lonhomework::showhash(%ConceptData);
-#$Apache::lonxml::debug=0;
-    my $Answ=&Apache::lonnet::ssi($uri);
-    $r->print("<br><b>Here you can see the Problem:</b><br>$Answ");
-}
-
-sub DrawTable {
-    my $k=shift;
-    my $Max=0;
-    my @data1;
-    my @data2;
-    my $Correct=0;
-    my $Wrong=0;
-    for (my $n=0; $n<=$#Concepts; $n++ ) {
-	my $tmp=$Concepts[$n];
-	$data1[$n]=$ConceptData{"$tmp.$k.true"};
-	$Correct+=$data1[$n];
-	$data2[$n]=$ConceptData{"$tmp.$k.false"};
-	$Wrong+=$data2[$n];
-	my $Sum=$data1[$n]+$data2[$n];
-	if ( $Max<$Sum ) {$Max=$Sum;}
-    }
-    for (my $n=0; $n<=$#Concepts; $n++ ) {
-	if ($data1[$n]+$data2[$n]<$Max) {
-	    $data2[$n]+=$Max-($data1[$n]+$data2[$n]);
-	}
-    }
-    my $P_No = $#data1+1;
-#    $r->print('<br><b>From: ['.localtime($ConceptData{'Int.'.($k-1)}).
-#              '] To: ['.localtime($ConceptData{"Int.$k"}).']</b>'); 
-    my $Str = "\n".'<table border=2>'.
-              "\n".'<tr>'.
-              "\n".'<th> # </th>'.
-	      "\n".'<th> Concept </th>'.
-	      "\n".'<th> Correct </th>'.
-	      "\n".'<th> Wrong </th>'.
-	      "\n".'</tr>';
-
-    for (my $n=0; $n<=$#Concepts; $n++ ) {
-	$Str .= "\n"."<tr>".
-	        "\n"."<td>".($n+1)."</td>".
-                "\n".'<td bgcolor='.$color{"yellow"}.'> '.$Concepts[$n]." </td>".
-                "\n".'<td bgcolor='.$color{"green"}.'> '.$data1[$n]." </td>".
-                "\n".'<td bgcolor='.$color{"red"}.'> '.$data2[$n]." </td>".
-                "\n"."</tr>";
-    }
-    $Str.='<td></td><td><b>From:['.localtime($ConceptData{'Int.'.$k}).
-          '] To: ['.localtime($ConceptData{'Int.'.($k+1)}-1).
-          "]</b></td><td>$Correct</td><td>$Wrong</td>";
-
-    $Str .= "\n".'</table>';
-
-    $r->print($Str);
-#$Apache::lonxml::debug=1;
-#&Apache::lonhomework::showhash(%ConceptData);
-#$Apache::lonxml::debug=0;
-}
-
-
-sub DrawGraph {
-    my ($currentInterval,$title)=@_;
-    my $Max=0;
-    my @data1;
-    my @data2;
-
-    # Adjust Data and find the Max 
-    for(my $n=0; $n<=$#Concepts; $n++ ) {
-	my $tmp=$Concepts[$n];
-	$data1[$n]=$ConceptData{$tmp.'.'.$currentInterval.'.true'};
-	$data2[$n]=$ConceptData{$tmp.'.'.$currentInterval.'.false'};
-	my $Sum=$data1[$n]+$data2[$n];
-	if($Max < $Sum) { $Max = $Sum; }
-    }
-    for(my $n=0; $n<=$#Concepts; $n++) {
-	if($data1[$n]+$data2[$n]<$Max) {
-	    $data2[$n]+=$Max-($data1[$n]+$data2[$n]);
-	}
-    }
-    my $P_No = scalar @data1;
-
-    if($Max > 1) { 
-	$Max += (10 - $Max % 10);
-	$Max = int($Max);
-    } else { 
-        $Max = 1;
-    }
-
-    my $Titr=($ConceptData{'Interval'}>1) ? 
-        $title.'_interval_'.($currentInterval+1) : $title;
-#    $GData=$Titr.'&Concepts'.'&'.'Answers'.'&'.$Max.'&'.$P_No.'&'.$data1.'&'.$data2;
-    $GData  = $Titr.'&Concepts&Answers&'.$Max.'&'.$P_No.'&';
-    $GData .= (join(',',@data1)).'&'.(join(',',@data2));
-
-    $r->print('<IMG src="/cgi-bin/graph.gif?'.$GData.'" border=1/>');
-}
-
-
-sub Decide {
-    #deciding the true or false answer belongs to each interval
-    my ($type,$foil,$time)=@_; 
-    my $k=0;
-    while ($time>$ConceptData{'Int.'.($k+1)} && 
-           $k<$ConceptData{'Interval'}) {$k++;}
-    $ConceptData{"$foil_to_concept{$foil}.$k.$type"}++;
-}
-
-
-#restore the student submissions and finding the result
-sub OpStatus {
-    my ($problem, $student, $courseID)=@_;
-    my ($username,$userdomain)=split(/':'/,$student);
-    my $code='U';
-    my %reshash=&Apache::lonnet::restore($problem, $courseID, $userdomain, 
-                                         $username);
-    my @True = ();
-    my @False = ();
-    my $flag=0;
-    if ($reshash{'version'}) {
-        my $tries=0;
-	&Apache::lonhomework::showhash(%Answer);
-	for (my $version=1;$version<=$reshash{'version'};$version++) {
-	    my $time=$reshash{"$version:timestamp"};
-	   
-	    foreach my $key (sort(split(/\:/,$reshash{$version.':keys'}))) {
-		if (($key=~/\.(\w+)\.(\w+)\.submission$/)) {
-		    my $Id1 = $1; my $Id2 = $2;
-		    #check if this is a repeat submission, if so skip it
-          	    if ($reshash{"$version:resource.$Id1.previous"}) { next; }
-		    #if no solved this wasn't a real submission, ignore it
-		    if (!defined($reshash{"$version:resource.$Id1.solved"})) {
-			&Apache::lonxml::debug("skipping ");
-			next;
-		    }
-		    my $Resp = $reshash{"$version:$key"};
-		    my %submission=&Apache::lonnet::str2hash($Resp);
-		    foreach (keys %submission) {
-			my $Ansr = $Answer{"$Id1.$Id2.foil.value.$_"};
-			if ($submission{$_}) {
-			    if ($submission{$_} eq $Ansr) {
-				&Decide("true",$_,$time );
-			    }
-			    else {&Decide("false",$_,$time );}
-			}
-		    }
-	        }	  
-	    }
-        }
-    }
-}
-
-#---- END Analyze Web Page ----------------------------------------------
-
-#---- Problem Statistics Web Page ---------------------------------------
-
-#------- Processing upperlist and lowerlist according to each problem
-sub ProcessDiscriminant {
-    my ($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<$Count) {
-	($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).':'.$nStudent;
-	$Proc{$Temp}=($Sum1/$nStudent).':'.($Sum2/$nStudent);
-#       $r->print("$nIndex) $Temp --> ($nStudent) $Proc{$Temp} <br>");
-	$Sum1=0;
-	$Sum2=0;
-	$nStudent=0;
-    }
-
-    return %Proc;
-}
-
-
-#------- Creating Discimination factor   
-sub Discriminant {
-    my ($discriminantFactor)=@_;
-    my @discriminantKeys=keys(%$discriminantFactor);
-    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 $str=$discriminantFactor->{$key};
-            foreach(split(/\:/,$str)){
-                if($_) {
-                    if($low<$UpCnt) { push(@LowList,$_); }
-                    else            { push(@UpList,$_);  }
-                }
-            }
-        }
-    }
-    my %DisUp =  &ProcessDiscriminant(\@UpList);
-    my %DisLow = &ProcessDiscriminant(\@LowList);
-
-    return (\%DisUp, \%DisLow);
-}
-
-sub NumericSort {          
-    $a <=> $b;
-}
-
-sub CreateProblemStatisticsTableHeading {
-    my ($displayFormat,$sequenceSource,$sequenceTitle,$headings)=@_;
-    if($displayFormat eq 'Display CSV Format') {
-        $r->print('<br>"'.$sequenceTitle.'","');
-        $r->print($sequenceSource.'"');
-	return;
-    }
-
-    $r->print('<br><a href="'.$sequenceSource.
-              '" target="_blank">'.$sequenceTitle.'</a>');
-
-    my $Result = "\n".'<table border=2><tr><th>P#</th>'."\n";
-    for(my $nIndex=0; $nIndex < (scalar (keys %$headings)); $nIndex++) { 
-	$Result .= '<th>'.'<input type="submit" name="';
-        $Result .= 'ProblemStatisticsHeading" value="';
-        $Result .= $headings->{$nIndex}.'" />'.'</th>'."\n";
-    }
-    $Result .= "\n".'</tr>'."\n";    
-    $r->print($Result);
-    $r->rflush();
-}
-
-sub CloseTable {
-    my ($cache)=@_;
-    if($cache->{'DisplayFormat'} eq 'Display CSV Format') {
-	return;
-    }    
-    $r->print("\n".'</table>'."\n");
-    $r->rflush();
-}
-
-# ------ Dump the Student's DB file and handling the data for statistics table 
-sub ExtractStudentData {
-    my ($cache,$name)=@_;
-    my %discriminantFactor;
-    my @list=();
-
-    my $totalTries = 0;
-    my $totalAwarded = 0;
-    my $tempProblemOrder=0;
-    foreach my $sequence (split(':', $cache->{'orderedSequences'})) {
-        if($cache->{'ProblemStatisticsMap'} ne 'All Maps'  &&
-           $cache->{'ProblemStatisticsMap'} ne $cache->{$sequence.':title'}) {
-            next;
-        }
-
-        my $Dis = '';
-        foreach my $problemID (split(':', $cache->{$sequence.':problems'})) {
-            my $problem = $cache->{$problemID.':problem'};
-            my $LatestVersion = $cache->{$name.':version:'.$problem};
-
-            # Output dashes for all the parts of this problem if there
-            # is no version information about the current problem.
-            #if(!$LatestVersion) {
-            #    foreach my $part (split(/\:/,$cache->{$sequence.':'.
-            #                                          $problemID.
-            #                                          ':parts'})) {
-            #        $codes    .= "-,";
-            #        $attempts .= "0,"; 
-            #    }
-            #    next;
-            #}
-
-            my %partData=undef;
-            # Initialize part data, display skips correctly
-            # Skip refers to when a student made no submissions on that
-            # part/problem.
-            foreach my $part (split(/\:/,$cache->{$sequence.':'.
-                                                  $problemID.
-                                                  ':parts'})) {
-                $partData{$part.':tries'}=0;
-                $partData{$part.':code'}='-';
-            }
-
-            # Looping through all the versions of each part, starting with the
-            # oldest version.  Basically, it gets the most recent 
-            # set of grade data for each part.
-	    for(my $Version=1; $Version<=$LatestVersion; $Version++) {
-                foreach my $part (split(/\:/,$cache->{$sequence.':'.
-                                                      $problemID.
-                                                      ':parts'})) {
-
-                    if(!defined($cache->{$name.":$Version:$problem".
-                                               ":resource.$part.solved"})) {
-                        # No grade for this submission, so skip
-                        next;
-                    }
-
-                    my $tries=0;
-                    my $time=0;
-                    my $awarded=0;
-                    my $code='U';
-
-                    $awarded = $cache->{$name.
-                                        "$Version:$problem:resource.".
-                                        "$part.awarded"};
-                    $partData{$part.':awarded'} = ($awarded) ? $awarded : 0;
-                    $totalAwarded += $awarded;
-
-                    $tries = $cache->{$name.":$Version:$problem".
-                                      ":resource.$part.tries"};
-                    $partData{$part.':tries'} = ($tries) ? $tries : 0;
-                    $partData{$part.':wrong'} = $partData{$part.':tries'};
-                    $totalTries += $tries;
-
-                    my $val = $cache->{$name.":$Version:$problem".
-                                       ":resource.$part.solved"};
-                    if    ($val eq 'correct_by_student')   {$code = 'C';} 
-                    elsif ($val eq 'correct_by_override')  {$code = 'O';}
-                    elsif ($val eq 'incorrect_attempted')  {$code = 'I';} 
-                    elsif ($val eq 'incorrect_by_override'){$code = 'I';}
-                    elsif ($val eq 'excused')              {$code = 'x';}
-                    $partData{$part.':code'}=$code;
-
-                    if($partData{$part.':wrong'} ne 0 && 
-                       ($code eq 'C' || $code eq 'O')) {
-                        $partData{$part.':wrong'}--;
-                    }
-                }
-            }
-
-            # Loop through all the parts for the current problem in the 
-            # correct order and prepare the output
-            foreach (split(/\:/,$cache->{$sequence.':'.$problemID.
-                                         ':parts'})) {
-                my $Yes = 0;
-                if($partData{$_.':code'} eq 'C' || 
-                   $partData{$_.':code'} eq 'O') {
-                    $Yes=1;
-                }
-                #my $ptr = "$hash{'title_'.$ResId}";
-                my $ptr = $tempProblemOrder.'&'.$problemID;
-
-                if($_ > 1) {
-                    $ptr .= "*(part $_)";
-                    $Dis .= '&';
-                }
-                my $Fac = ($partData{$_.':Tries'}) ? 
-                    ($partData{$_.':awarded'}/$partData{$_.':tries'}) : 0;
-                my $DisF;
-                if($Fac > 0 &&  $Fac < 1) { 
-                    $DisF = sprintf( "%.4f", $Fac );
-                } else {
-                    $DisF = $Fac;
-                }
-                $Dis .= $tempProblemOrder.'='.$DisF.'+'.$Yes;
-                $ptr .= '&'.$partData{$_.'.Tries'}.
-                        '&'.$partData{$_.'.Wrongs'}.
-                        '&'.$partData{$_.'.Code'};
-                push (@list, $ptr);
-                $tempProblemOrder++;
-            }
-        }
-        if($totalTries) {
-	    my $DisFac = ($totalAwarded/$totalTries);
-	    my $DisFactor = sprintf( "%.4f", $DisFac );
-	    $discriminantFactor{$DisFactor}=$Dis;
-	}
-    }
-
-    return (\%discriminantFactor, \@list);
-}
-
-sub MySort {          
-    if ( $Pos > 0 ) {
-	if ($ENV{'form.order'} eq 'Descending') {$b <=> $a;}
-	else { $a <=> $b; }
-    }
-    else {
-	if ($ENV{'form.order'} eq 'Descending') {$b cmp $a;}
-	else { $a cmp $b; }
-    }
-}
-
-sub BuildStatisticsTable {
-    my ($cache,$discriminantFactor,$list,$headings)=@_;
-
-    my $p_count = 0;
-    my $nIndex = 0;
-    my $dummy;
-    my $p_val;
-    my $ResId;
-    my $NoElements = scalar @$list;
-
-    foreach my $sequence (split(':', $cache->{'orderedSequences'})) {
-        if($cache->{'ProblemStatisticsMap'} ne 'All Maps'  &&
-           $cache->{'ProblemStatisticsMap'} ne $cache->{$sequence.':title'}) {
-            next;
-        }
-
-	&CreateProblemStatisticsTableHeading($cache->{'DisplayFormat'},
-                                             $cache->{$sequence.':source'}, 
-                                             $cache->{$sequence.':title'},
-                                             $headings);
-	my ($Hid,$pr)=split(/\:/,$mapsort{$_});
-	my @lpr=split(/\&/,$pr);
-	for (my $i=1; $i<=$#lpr; $i++) {
-	    my %storestats=();
-	    my ($PrOrd,$Prob,$Tries,$Wrongs,$Code)=split(/\&/,$list->[$nIndex]);
-	    my $Temp = $Prob;
-	    my $MxTries = 0;
-	    my $TotalTries = 0;
-	    my $YES = 0;
-	    my $Incorrect = 0;
-	    my $Override = 0;
-	    my $StdNo = 0;
-	    my @StdLst;
-	    while ( $PrOrd == $lpr[$i] ) 
-	    {
-		$nIndex++;
-		$StdNo++;
-		$StdLst[ $StdNo ] = $Tries;
-		$TotalTries += $Tries;
-		if ( $MxTries < $Tries ) { $MxTries = $Tries; } 
-		if ( $Code eq 'C' ){ $YES++; }
-		elsif( $Code eq 'I' ) { $Incorrect++; }
-		elsif( $Code eq 'O' ) { $Override++; }
-		elsif( $Code eq 'U' ) { $StdNo--; }
-		($PrOrd,$Prob,$Tries,$Wrongs,$Code)=split(/\&/,$list->[$nIndex]);
-	    }	
-
-	    $p_count++;
-	    my $Dummy;
-	    ($ResId,$Dummy)=split(/\*/,$Temp);
-
-	    $Temp = '<a href="'.$hash{'src_'.$ResId}.
-                '" target="_blank">'.$hash{'title_'.$ResId}.$Dummy.'</a>';
-
-	    my $res = &Apache::lonnet::declutter($hash{'src_'.$ResId});
-	    my $urlres=$res;
-
-	    $ResId=~/(\d+)\.(\d+)/;
-	    my $Map = &Apache::lonnet::declutter( $hash{'map_id_'.$1} );
-	    $urlres=$Map;
- 
-	    $res = '<a href="'.$hash{'src_'.$ResId}.'">'.$res.'</a>';
-	    #$Map = '<a href="'.$Map.'">'.$res.'</a>';
-
-#------------------------ Compute the Average of Tries about one problem
-	    my $Average = ($StdNo) ? $TotalTries/$StdNo : 0;
-
-	    $storestats{$ENV{'request.course.id'}.'___'.$urlres.'___timestamp'}=time;       
-	    $storestats{$ENV{'request.course.id'}.'___'.$urlres.'___stdno'}=$StdNo;
-	    $storestats{$ENV{'request.course.id'}.'___'.$urlres.'___avetries'}=$Average;
-   
-#-------------------------------- Compute percentage of Wrong tries
-	    my $Wrong = ( $StdNo ) ? 100 * ( $Incorrect / $StdNo ) : 0;
-
-#-------------------------------- Compute Standard Deviation
-	    my $StdDev = 0; 
-	    if ( $StdNo > 1 ) {
-		for ( my $n = 0; $n < $StdNo; $n++ ) {
-		    my $Dif = $StdLst[ $n ]-$Average;
-		    $StdDev += $Dif*$Dif;
-		} 
-		$StdDev /= ( $StdNo - 1 );
-		$StdDev = sqrt( $StdDev );
-	    }
-
-#-------------------------------- Compute Degree of Difficulty
-	    my $DoDiff = 0;
-	    if( $TotalTries > 0 ) {
-		$DoDiff = 1 - ( ( $YES + $Override ) / $TotalTries );
-#	    $DoDiff =  ($TotalTries)/($YES + $Override+ 0.1);	    
-	    }
-       
-	    $storestats{$ENV{'request.course.id'}.'___'.$urlres.'___difficulty'}=$DoDiff;
-
-#-------------------------------- Compute the Skewness
-	    my $Skewness = 0;
-	    my $Sum = 0; 
-	    if ( $StdNo > 0 && $StdDev > 0 ) {
-		for ( my $n = 0; $n < $StdNo; $n++ ) {
-		    my $Dif = $StdLst[ $n ]-$Average;
-		    $Skewness += $Dif*$Dif*$Dif;
-		} 
-		$Skewness /= $StdNo;
-		$Skewness /= $StdDev*$StdDev*$StdDev;
-	    }
-
-#--------------------- Compute the Discrimination Factors
-            my ($Up1,$Up2)=split(/\:/,':');#jason$DisUp->{$lpr[$i]});
-	    my ($Lw1,$Lw2)=split(/\:/,':');#jason$DisLow->{$lpr[$i]});
-	    my $Dis1 = $Up1 - $Lw1;
-	    my $Dis2 = $Up2 - $Lw2;
-	    my $_D1 = sprintf("%.2f", $Dis1);
-	    my $_D2 = sprintf("%.2f", $Dis2);
-
-#-----------------  Some restition in presenting the float numbers
-	    my $Avg = sprintf( "%.2f", $Average );
-	    my $Wrng = sprintf( "%.1f", $Wrong );
-	    my $SD = sprintf( "%.1f", $StdDev );
-	    my $DoD = sprintf( "%.2f", $DoDiff );
-	    my $Sk = sprintf( "%.1f", $Skewness );
-	    my $join = $lpr[$i].'&'.$Temp.'&'.$StdNo.'&'.
-                       $TotalTries.'&'.$MxTries.'&'.$Avg.'&'.
-                       $YES.'&'.$Override.'&'.$Wrng.'&'.$DoD.'&'.
-		       $SD.'&'.$Sk.'&'.$_D1.'&'.$_D2.'&'.
-                       $Prob;
-	    $CachData{($p_count-1)}=$join;
-
-	    $urlres=~/^(\w+)\/(\w+)/;
-	    if ($StdNo) { 
-		&Apache::lonnet::put('resevaldata',\%storestats,$1,$2); 
-	    }
-#-------------------------------- Row of statistical table
-            &TableRow($cache,$join,$i,($p_count-1));
-	}
-	&CloseTable($cache);
-    }
-    &Close_PrgWin();
-}
-
-=pod
-sub Cache_Statistics {
-    my ($cache)=@_;
-    my @list = ();
-    my $Useful;
-    my $UnUseful;
-#    $r->print('<input type="hidden" name="show" value="excel" />'."\n"); 
-    my %myHeader = reverse( %Header );
-    $Pos = $myHeader{$ENV{'form.sort'}};
-    if ($Pos > 0) {$Pos++;}
-    my $p_count = 0;
-    foreach my $key( keys %CachData) { 
-	my @Temp=split(/\&/,$CachData{$key});
-	if ( $Pos == 0 ) {
-	    ($UnUseful,$Useful)=split(/\>/,$Temp[$Pos]);
-	}
-	else {
-	    $Useful = $Temp[$Pos];
-	}   
-	$list[$p_count]=$Useful.'@'.$CachData{$key};
-        $p_count++;
-    }
-
-    @list = sort MySort (@list);
-
-    my $nIndex=0;
-
-    if ( $Pos == 0 ) {
-	foreach (sort keys %mapsort) {
-	    my ($Hid,$pr)=split(/\:/,$mapsort{$_});
-	    &CreateProblemStatisticsTableHeading($cache,1,$Hid);
-	    my @lpr=split(/\&/,$pr);
-	    for (my $i=1; $i<=$#lpr; $i++) {
-		my($Pre, $Post) = split(/\@/,$list[$nIndex]); 
-		#$r->print('<br>'.$Pre.'---'.$Post);
-		&TableRow($cache,$Post,$i,$nIndex);
-		$nIndex++;
-	    }
-	    &CloseTable($cache);
-	}
-    }
-    else {
-	&CreateProblemStatisticsTableHeading($cache,0);
-	for ( my $nIndex = 0; $nIndex < $p_count; $nIndex++ ) {
-	    my($Pre, $Post) = split(/\@/,$list[$nIndex]); 
-	    &TableRow($cache,$Post,$nIndex,$nIndex);
-	} 
-	&CloseTable($cache);
-    }
-}
-=cut
-sub TableRow {
-    my ($cache,$Str,$Idx,$RealIdx)=@_;
-    my($PrOrd,$Temp,$StdNo,$TotalTries,$MxTries,$Avg,$YES,$Override,
-       $Wrng,$DoD,$SD,$Sk,$_D1,$_D2,$Prob)=split(/\&/,$Str);	
-    if($cache->{'DisplayFormat'} eq 'Display CSV Format') {
-        my ($ResId,$Dummy)=split(/\*/,$Prob);
-        my $Ptr =  "\n".'<br>'.
-               "\n".'"'.($RealIdx+1).'",'.
-               "\n".'"'.$hash{'title_'.$ResId}.$Dummy.'",'.
-               "\n".'"'.$hash{'src_'.$ResId}.'",'.
-               "\n".'"'.$StdNo.'",'.
-               "\n".'"'.$TotalTries.'",'.
-               "\n".'"'.$MxTries.'",'.
-               "\n".'"'.$Avg.'",'.
-               "\n".'"'.$YES.'",'.
-               "\n".'"'.$Override.'",'.
-               "\n".'"'.$Wrng.'",'.
-               "\n".'"'.$DoD.'",'.
-               "\n".'"'.$SD.'",'.
-               "\n".'"'.$Sk.'",'.
-               "\n".'"'.$_D1.'",'.
-	       "\n".'"'.$_D2.'"';
-        $r->print("\n".$Ptr);
-    } else {
-        my $Ptr =  "\n".'<tr>'.
-               "\n".'<td>'.($RealIdx+1).'</td>'.
-          #     "\n".'<td>'.$PrOrd.$Temp.'</td>'.
-               "\n".'<td>'.$Temp.'</td>'.
-               "\n".'<td bgcolor='.$color{"yellow"}.'> '.$StdNo.'</td>'.
-               "\n".'<td bgcolor='.$color{"yellow"}.'>'.$TotalTries.'</td>'.
-               "\n".'<td bgcolor='.$color{"yellow"}.'>'.$MxTries.'</td>'.
-               "\n".'<td bgcolor='.$color{"gb"}.'>'.$Avg.'</td>'.
-               "\n".'<td bgcolor='.$color{"gb"}.'> '.$YES.'</td>'.
-               "\n".'<td bgcolor='.$color{"gb"}.'> '.$Override.'</td>'.
-               "\n".'<td bgcolor='.$color{"red"}.'> '.$Wrng.'</td>'.
-               "\n".'<td bgcolor='.$color{"red"}.'> '.$DoD.'</td>'.
-               "\n".'<td bgcolor='.$color{"green"}.'> '.$SD.'</td>'.
-               "\n".'<td bgcolor='.$color{"green"}.'> '.$Sk.'</td>'.
-               "\n".'<td bgcolor='.$color{"purple"}.'> '.$_D1.'</td>'.
-	       "\n".'<td bgcolor='.$color{"purple"}.'> '.$_D2.'</td>';
-        $r->print("\n".$Ptr.'</tr>' );
-    }
-    $GraphDat{$RealIdx}=$DoD.':'.$Wrng;
-}
-
-sub StatusOptions {
-    my ($cache)=@_;
-
-    my $Status = $cache->{'Status'};
-    my $OpSel1 = '';
-    my $OpSel2 = '';
-    my $OpSel3 = '';
-
-    if($Status eq 'Any')         { $OpSel3 = ' selected'; }
-    elsif($Status eq 'Expired' ) { $OpSel2 = ' selected'; }
-    else                         { $OpSel1 = ' selected'; }
-
-    my $Ptr = '';
-    $Ptr .= '<tr><td align="right"><b>Student Status:</b></td>'."\n";
-    $Ptr .= '<td align="left"><select name="Status">';
-    $Ptr .= '<option'.$OpSel1.'>Active</option>'."\n";
-    $Ptr .= '<option'.$OpSel2.'>Expired</option>'."\n";
-    $Ptr .= '<option'.$OpSel3.'>Any</option>'."\n";
-    $Ptr .= '</select></td></tr>'."\n";
-
-    return $Ptr;
-}
-
-sub AscendOrderOptions {
-    my ($cache)=@_;
-
-    my $order = $cache->{'Ascend'};
-    my $OpSel1 = '';
-    my $OpSel2 = '';
-
-    if($order eq 'Ascending') {
-        $OpSel1 = ' selected';
-    } else {
-        $OpSel2 = ' selected';
-    }
-
-    my $Ptr = '';
-    $Ptr .= '<tr><td align="right"><b>Sorting Type:</b></td>'."\n";
-    $Ptr .= '<td align="left"><select name="Ascend">'."\n";
-    $Ptr .= '<option'.$OpSel1.'>Ascending</option>'."\n".
-	    '<option'.$OpSel2.'>Descending</option>'."\n";
-    $Ptr .= '</select></td></tr>'."\n";
-
-    return $Ptr;
-}
-
-sub ProblemStatisticsButtons {
-    my ($cache)=@_;
-
-    my $Ptr = '<tr><td></td><td align="left">';
-    $Ptr .= '<input type=submit name="ProblemStatisticsRecalculate" ';
-    $Ptr .= 'value="Recalculate Statistics"/>'."\n";
-    $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="DoDiffGraph" ';
-    $Ptr .= 'value="DoDiff Graph" />'."\n";
-    $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="PercentWrongGraph" ';
-    $Ptr .= 'value="%Wrong Graph" />'."\n";
-    $Ptr .= '&nbsp;&nbsp;&nbsp;';
-    $Ptr .= '<input type="submit" name="DisplayCSVFormat" ';
-    if($cache->{'DisplayFormat'} eq 'Display CSV Format') {
-        $Ptr .= 'value="Display CSV Format" />'."\n";
-    } else {
-        $Ptr .= 'value="Display Table Format" />'."\n";
-    }
-    $Ptr .= '</td></tr>';
-
-    return $Ptr;
-}
-
-sub ProblemStatisticsLegend {
-    my $Ptr = '';
-    $Ptr = '<table border="0">';
-    $Ptr .= '<tr><td>';
-    $Ptr .= '<b>#Stdnts</b>:</td>';
-    $Ptr .= '<td>Total Number of Students opened the problem.';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>Tries</b>:</td>';
-    $Ptr .= '<td>Total Number of Tries for solving the problem.';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>Mod</b>:</td>';
-    $Ptr .= '<td>Maximunm Number of Tries for solving the problem.';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>Mean</b>:</td>';
-    $Ptr .= '<td>Average Number of the tries. [ Tries / #Stdnts ]';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>#YES</b>:</td>';
-    $Ptr .= '<td>Number of students solved the problem correctly.';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>#yes</b>:</td>';
-    $Ptr .= '<td>Number of students solved the problem by override.';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>%Wrng</b>:</td>';
-    $Ptr .= '<td>Percentage of students tried to solve the problem ';
-    $Ptr .= 'but still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]';
-    $Ptr .= '</td></tr><tr><td>';
-#    Kashy formula
-#    '<b>  DoDiff </b>: Degree of Difficulty of the problem.<br>'.
-#    '[ Tries/(#YES+#yes+0.1) ]<br>'.
-    #Gerd formula
-    $Ptr .= '<b>DoDiff</b>:</td>';
-    $Ptr .= '<td>Degree of Difficulty of the problem.  ';
-    $Ptr .= '[ 1 - ((#YES+#yes) / Tries) ]';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>S.D.</b>:</td>';
-    $Ptr .= '<td>Standard Deviation of the tries.  ';
-    $Ptr .= '[ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1) ';
-    $Ptr .= 'where Xi denotes every student\'s tries ]';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>Skew.</b>:</td>';
-    $Ptr .= '<td>Skewness of the students tries.';
-    $Ptr .= '[(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]';
-    $Ptr .= '</td></tr><tr><td>';
-    $Ptr .= '<b>Dis.F.</b>:</td>';
-    $Ptr .= '<td>Discrimination Factor: A Standard for evaluating the ';
-    $Ptr .= 'problem according to a Criterion<br>';
-    $Ptr .= '<b>[Applied Criterion in %27 Upper Students - ';
-    $Ptr .= 'Applied the same Criterion in %27 Lower Students]</b><br>';
-    $Ptr .= '<b>1st Criterion</b> for Sorting the Students: ';
-    $Ptr .= '<b>Sum of Partial Credit Awarded / Total Number of Tries</b><br>';
-    $Ptr .= '<b>2nd Criterion</b> for Sorting the Students: ';
-    $Ptr .= '<b>Total number of Correct Answers / Total Number of Tries</b>';
-    $Ptr .= '</td></tr></table>';
-
-    return $Ptr;
-}
-
-#---- END Problem Statistics Web Page ----------------------------------------
-
-#---- Problem Statistics Graph Web Page --------------------------------------
-
-sub GetGraphData {
-    my ($whichGraph, $courseID)=@_;
-    my $Col=0;
-    my $graphTitle='';
-    my $data='';
-    my $count = 0;
-    my $Max = 0;
-    my $graphData='Graph data does not exist.';
-    my $GraphDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
-                  "_$ENV{'user.domain'}_$courseID\_graph.db";
-    if(-e $GraphDB) {
-	if(tie(%GraphDat,'GDBM_File',"$GraphDB",&GDBM_READER,0640)) {
-	    if($whichGraph eq 'DiffGraph') {
-		$graphTitle = 'Degree-of-Difficulty';
-		$Col = 0;
-	    } else {
-		$graphTitle = 'Wrong-Percentage';
-		$Col = 1;
-	    }
-	    foreach (sort NumericSort keys %GraphDat) { 
-		my @Temp=split(/\:/,$GraphDat{$_});
-                my $inf = $Temp[$Col]; 
-		if($Max < $inf) {
-                    $Max = $inf;
-                }
-		$data .= $inf.',';
-		$count++;
-	    }
-	    if($Max > 1) { 
-		$Max += (10 - $Max % 10);
-		$Max = int($Max);
-	    } else { 
-                $Max = 1;
-            }
-            untie(%GraphDat);
-	    my $Course = $ENV{'course.'.$courseID.'.description'};
-	    $Course =~ s/\ /"_"/eg;
-	    $graphData  = $Course.'&'.'Problems'.'&'.$graphTitle.'&'.$Max.'&';
-            $graphData .= $count.'&'.$data;
-	} else {
-	    $graphData = "Unable to tie hash to db file";
-	}
-    }
-
-    return $graphData;
-}
-
-#---- END Problem Statistics Graph Web Page ----------------------------------
-
-#---- Problem Analysis Web Page ----------------------------------------------
-
-sub IntervalOptions {
-    my ($cache)=@_;
-
-    my $interval = 1;
-    for(my $n=1; $n<=7; $n++) {
-        if($cache->{'Interval'} == $n) {
-            $interval = $n;
-        }
-    }
-
-    my $Ptr = '<br><b>Select number of intervals</b>'."\n".
-       	      '<select name="Interval">'."\n";
-    for(my $n=1; $n<=7;$ n++) {
-	$Ptr .= '<option';
-        if($interval == $n) {
-            $Ptr .= ' selected';
-        }
-	$Ptr .= '>'.$n."</option>"."\n";
-    }
-    $Ptr .= '</select>'."\n";
-
-    return $Ptr;
-}
-
-sub OptionResponseTable {
-    my ($cache)=@_;
-    my $Str = '';
-    $Str .= '<br><b> Option Response Problems in this course:</b>'."\n";
-    $Str .= '<br><br>'."\n";
-    $Str .= "<table border=2><tr><th> \# </th><th> Problem Title </th>";
-    $Str .= '<th> Resource </th><th> Analysis  </th></tr>'."\n";
-
-    my $number=1;
-    foreach (split(':::',$cache->{'OptionResponses'})) {
-        my ($uri,$title,$part,$problem)=split('::',$_);
-        my $Temp = '<a href="'.$uri.'" target="_blank">'.$title.'</a>';
-        $Str .= '<tr>';
-        $Str .= '<td> '.$number.' </td>';
-        $Str .= '<td bgcolor="'.$color{"green"}.'"> '.$Temp.' </td>';
-        $Str .= '<td bgcolor="'.$color{"yellow"}.'"> '.$uri.' </td>';
-        $Str .= '<td><input type="submit" name="Analyze:::'.$uri.':::';
-        $Str .= $title.':::'.$part.':::'.$problem.'" value="';
-        $Str .= 'Analyze" /></td></tr>'."\n";
-        $number++;
-    }
-    $Str .= '</table>'."\n";
-
-    return $Str;
-}
-
-#---- END Problem Analysis Web Page ------------------------------------------
-
-#---- Student Assessment Web Page --------------------------------------------
-
-sub MapOptions {
-    my ($cache, $page)=@_;
-    my $Ptr = '<tr>';
-    $Ptr .= '<td align="right"><b>Select Map</b></td>'."\n";
-    $Ptr .= '<td align="left"><select name="Maps">'."\n";
-
-    my $selected = 0;
-    foreach my $sequence (split(':',$cache->{'orderedSequences'})) {
-	$Ptr .= '<option';
-        if($cache->{$page.'Map'} eq $cache->{$sequence.':title'}) {
-            $Ptr .= ' selected';
-            $selected = 1;
-        }
-	$Ptr .= '>'.$cache->{$sequence.':title'}.'</option>'."\n";	     
-    }
-    $Ptr .= '<option';
-    if(!$selected) {
-        $Ptr .= ' selected';
-    }
-    $Ptr .= '>All Maps</option>'."\n";
-
-    $Ptr .= '</select></td></tr>'."\n";
-
-    return $Ptr;
-}
-
-sub StudentOptions {
-    my ($students, $selectedName)=@_;
-
-    my $Ptr ='<tr>';
-    $Ptr .= '<td align="right"><b>Select Student</b></td>'."\n";
-    $Ptr .= '<td align="left"><select name="Students">'."\n";
-
-    my $selected=0;
-    foreach (@$students) {
-        my ($name) = split(':',$_);
-	$Ptr .= '<option';
-	if($selectedName eq $name) {
-            $Ptr .= ' selected';
-            $selected = 1;
-        }
-        $Ptr .= '>'.$name.'</option>'."\n";	     
-    }
-
-    $Ptr .= '<option';
-    if(!$selected) {
-        $Ptr .= ' selected';
-    }
-    $Ptr .= '>No Student Selected</option>'."\n";
-
-    $Ptr .= '</select></td></tr>'."\n";
-
-    return $Ptr;
-}
-
-# ------ Create different Student Report 
-sub StudentReport {
-    my ($cache, $name)=@_;
-
-    my $Str = '';
-    if($cache->{$name.':error'} =~ /course/) {
-        my ($username)=split(':',$name);
-        $Str .= '<b><font color="blue">No course data for student </font>';
-        $Str .= '<font color="red">'.$username.'.</font></b><br>';
-        return $Str;
-    }
-
-    $Str .= "<table border=2><tr><th> \# </th><th> Set Title </th>";
-    $Str .= '<th> Results </th><th> Tries </th></tr>'."\n";
-
-    my $codes;
-    my $attempts;
-    foreach my $sequence (split(':', $cache->{'orderedSequences'})) {
-        if($cache->{'StudentAssessmentMap'} ne 'All Maps'  &&
-           $cache->{'StudentAssessmentMap'} ne $cache->{$sequence.':title'}) {
-            next;
-        }
-
-        $Str .= '<tr><td>'.$sequence.'</td>';
-        $Str .= '<td>'.$cache->{$sequence.':title'}.'</td>';
-
-        $codes = '';
-        $attempts = '';
-        foreach my $problemID (split(':', $cache->{$sequence.':problems'})) {
-            my $problem = $cache->{$problemID.':problem'};
-            my $LatestVersion = $cache->{$name.':version:'.$problem};
-
-            # Output dashes for all the parts of this problem if there
-            # is no version information about the current problem.
-            if(!$LatestVersion) {
-                foreach my $part (split(/\:/,$cache->{$sequence.':'.
-                                                      $problemID.
-                                                      ':parts'})) {
-		    $codes    .= "-,";
-                    $attempts .= "0,"; 
-                }
-                next;
-            }
-
-            my %partData=undef;
-            # Initialize part data, display skips correctly
-            # Skip refers to when a student made no submissions on that
-            # part/problem.
-            foreach my $part (split(/\:/,$cache->{$sequence.':'.
-                                                  $problemID.
-                                                  ':parts'})) {
-                $partData{$part.':tries'}=0;
-                $partData{$part.':code'}='-';
-            }
-
-            # Looping through all the versions of each part, starting with the
-            # oldest version.  Basically, it gets the most recent 
-            # set of grade data for each part.
-	    for(my $Version=1; $Version<=$LatestVersion; $Version++) {
-                foreach my $part (split(/\:/,$cache->{$sequence.':'.
-                                                      $problemID.
-                                                      ':parts'})) {
-
-                    if(!defined($cache->{$name.":$Version:$problem".
-                                               ":resource.$part.solved"})) {
-                        # No grade for this submission, so skip
-                        next;
-                    }
-
-                    my $tries=0;
-                    my $code='U';
-
-                    $tries = $cache->{$name.":$Version:$problem".
-                                      ":resource.$part.tries"};
-                    $partData{$part.':tries'}=($tries) ? $tries : 0;
-
-                    my $val = $cache->{$name.":$Version:$problem".
-                                       ":resource.$part.solved"};
-                    if    ($val eq 'correct_by_student')   {$code = 'Y';} 
-                    elsif ($val eq 'correct_by_override')  {$code = 'y';}
-                    elsif ($val eq 'incorrect_attempted')  {$code = 'N';} 
-                    elsif ($val eq 'incorrect_by_override'){$code = 'N';}
-                    elsif ($val eq 'excused')              {$code = 'x';}
-                    $partData{$part.':code'}=$code;
-                }
-            }
-
-            # Loop through all the parts for the current problem in the 
-            # correct order and prepare the output
-            foreach (split(/\:/,$cache->{$sequence.':'.$problemID.
-                                         ':parts'})) {
-                $codes    .= $partData{$_.':code'}.',';
-                $attempts .= $partData{$_.':tries'}.','; 
-            }
-        }
-        $codes    =~ s/,$//;
-        $attempts =~ s/,$//;
-        $Str .= '<td>'.$codes.'</td>';
-        $Str .= '<td>'.$attempts.'</td>';
-        $Str .= '</tr>'."\n";
-    }
-
-    $Str .= '</table>'."\n";
-
-    return $Str;
-}
-
-#---- END Student Assessment Web Page ----------------------------------------
-
-#---- Menu Web Page ----------------------------------------------------------
-
-sub Title {
-    my ($downloadTime)=@_;
-
-    my $Ptr = '';
-
-    $Ptr .= '<html><head><title>LON-CAPA Statistics</title></head>'."\n";
-    $Ptr .= '<body bgcolor="#FFFFFF">'."\n";
-    $Ptr .= '<script>window.focus(); window.width=500;window.height=500;';
-    $Ptr .= '</script>'."\n";
-    $Ptr .= '<img align=right src=/adm/lonIcons/lonlogos.gif>'."\n";
-    $Ptr .= '<h1> Course : "';
-    $Ptr .= $ENV{'course.'.$ENV{'request.course.id'}.'.description'};
-    $Ptr .= '"</h1>'."\n";
-    $Ptr .= '<h3>'.$downloadTime.'</h3>';
-
-    return $Ptr;
-}
-
-sub CreateMenuForm {
-    my ($cache)=@_;
-    my $Ptr = '<table border="0">';
-    $Ptr .= '<tr><td><input type="submit" name="ProblemStatistics" ';
-    $Ptr .= 'value="Problem Stats"/>';
-    $Ptr .= '</td></tr>'."\n";
-
-    if(defined($cache->{'OptionResponses'})) {
-        $Ptr .= '<tr><td><input type="submit" name="ProblemAnalysis" ';
-        $Ptr .= 'value="Problem Analysis"/>';
-        $Ptr .= '</td></tr>'."\n";
-    }
-
-    $Ptr .= '<tr><td><input type="submit" name="StudentAssessment" ';
-    $Ptr .= 'value="Student Assessment"/>';
-    $Ptr .= '</td></tr>'."\n";
-    #$Ptr .= '<input type="submit" name="ActivityLog" value="Activity Log"/>';
-
-    $Ptr .= '</table>'."\n";
-
-    return $Ptr;
-}
-
-#---- END Menu Web Page ------------------------------------------------------
-
-#---- HELPER FUNCTIONS -------------------------------------------------------
 
 sub CheckFormElement {
     my ($cache, $ENVName, $cacheName, $default)=@_;
@@ -1303,67 +64,137 @@ sub CheckFormElement {
 }
 
 sub ProcessFormData{
-    my ($cacheDB, $isCached)=@_;
-    my %cache;
-
-    if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT,0640)) {
-        # Select page to display
-        if(defined($ENV{'form.ProblemStatistics'}) ||
-           defined($ENV{'form.ProblemStatisticsRecalculate'}) || 
-           defined($ENV{'form.DisplayCSVFormat'})) {
-            $cache{'GoToPage'} = 'ProblemStatistics';
-            &CheckFormElement(\%cache, 'DisplayCSVFormat',
-                              'DisplayFormat', 'Display Table Format');
-            &CheckFormElement(\%cache, 'Ascend','ProblemStatisticsAscend',
-                              'Ascending');
-            &CheckFormElement(\%cache, 'Maps', 'ProblemStatisticsMap', 
-                              'All Maps');
-        } elsif(defined($ENV{'form.ProblemAnalysis'})) {
-            $cache{'GoToPage'} = 'ProblemAnalysis';
-            &CheckFormElement(\%cache, 'Interval', 'Interval', '1');
-        } elsif(defined($ENV{'form.StudentAssessment'}) ||
-                defined($ENV{'form.CreateStudentAssessment'}) ||
-                defined($ENV{'form.NextStudent'}) ||
-                defined($ENV{'form.PreviousStudent'})) {
-            $cache{'GoToPage'} = 'StudentAssessment';
-            if(defined($ENV{'form.NextStudent'})) {
-                $cache{'StudentAssessmentMove'} = 'next';
-            } elsif(defined($ENV{'form.PreviousStudent'})) {
-                $cache{'StudentAssessmentMove'} = 'previous';
-            } else {
-                $cache{'StudentAssessmentMove'} = 'selected';
-            }
-            &CheckFormElement(\%cache, 'Maps', 'StudentAssessmentMap', 
-                              'All Maps');
-
-            &CheckFormElement(\%cache, 'Students', 'StudentAssessmentStudent', 
-                              'No Student Selected');
-        } elsif(defined($ENV{'form.DoDiffGraph'})) {
-            $cache{'GoToPage'} = 'DoDiffGraph';
-        } elsif(defined($ENV{'form.PercentWrongGraph'})) {
-            $cache{'GoToPage'} = 'PercentWrongGraph';
-        } elsif(defined($ENV{'form.ActivityLog'})) {
-            $cache{'GoToPage'} = 'ActivityLog';
-        } else {
-            $cache{'GoToPage'} = 'Menu';
-        }
-
-        &CheckFormElement(\%cache, 'Status', 'Status', 'Active');
+    my ($cache)=@_;
 
-        foreach (keys(%ENV)) {
-            if(/form\.Analyze:::/) {
-                $cache{'GoToPage'} = 'Analyze';
-                my ($uri, $title, $part, $problem);
-                (undef, $uri, $title, $part, $problem)=split(':::', $_);
-                $cache{'AnalyzeURI'}     = $uri;
-                $cache{'AnalyzeTitle'}   = $title;
-                $cache{'AnalyzePart'}    = $part;
-                $cache{'AnalyzeProblem'} = $problem;
+    $cache->{'reportKey'} = 'false';
 
-                &CheckFormElement(\%cache, 'Interval', 'Interval', '1');
-            }
-        }
+    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
+                                            ['sort','download',
+                                             'reportSelected',
+                                             'StudentAssessmentStudent',
+                                             'ProblemStatisticsSort']);
+    &CheckFormElement($cache, 'Status', 'Status', 'Active');
+    &CheckFormElement($cache, 'postdata', 'reportSelected', 'Class list');
+    &CheckFormElement($cache, 'reportSelected', 'reportSelected', 
+                      'Class list');
+    $cache->{'reportSelected'} = 
+        &Apache::lonnet::unescape($cache->{'reportSelected'});
+    &CheckFormElement($cache, 'DownloadAll', 'DownloadAll', 'false');
+    &CheckFormElement($cache, 'sort', 'sort', 'fullname');
+    &CheckFormElement($cache, 'download', 'download', 'false');
+    &CheckFormElement($cache, 'StatisticsMaps', 
+                      'StatisticsMaps', 'All Maps');
+    if(defined($ENV{'form.Section'})) {
+        my @sectionsSelected = (ref($ENV{'form.Section'}) ?
+                               @{$ENV{'form.Section'}} :
+                                ($ENV{'form.Section'}));
+        $cache->{'sectionsSelected'} = join(':', @sectionsSelected);
+    } elsif(!defined($cache->{'sectionsSelected'})) {
+        $cache->{'sectionsSelected'} = $cache->{'sectionList'};
+    }
+
+    # student assessment
+    if(defined($ENV{'form.CreateStudentAssessment'}) ||
+       defined($ENV{'form.NextStudent'}) ||
+       defined($ENV{'form.PreviousStudent'})) {
+        $cache->{'reportSelected'} = 'Student Assessment';
+    }
+    if(defined($ENV{'form.NextStudent'})) {
+        $cache->{'StudentAssessmentMove'} = 'next';
+    } elsif(defined($ENV{'form.PreviousStudent'})) {
+        $cache->{'StudentAssessmentMove'} = 'previous';
+    } else {
+        $cache->{'StudentAssessmentMove'} = 'selected';
+    }
+    &CheckFormElement($cache, 'StudentAssessmentStudent', 
+                      'StudentAssessmentStudent', 'All Students');
+    $cache->{'StudentAssessmentStudent'} = 
+        &Apache::lonnet::unescape($cache->{'StudentAssessmentStudent'});
+    &CheckFormElement($cache, 'DefaultColumns', 'DefaultColumns', 'false');
+
+    # Problem analysis
+    &CheckFormElement($cache, 'Interval', 'Interval', '1');
+
+    # ProblemStatistcs
+    &CheckFormElement($cache, 'DisplayCSVFormat',
+                      'DisplayFormat', 'Display Table Format');
+    &CheckFormElement($cache, 'ProblemStatisticsAscend',
+                      'ProblemStatisticsAscend', 'Ascending');
+    &CheckFormElement($cache, 'ProblemStatisticsSort',
+                      'ProblemStatisticsSort', 'Homework Sets Order');
+    &CheckFormElement($cache, 'DisplayLegend', 'DisplayLegend', 'Hide Legend');
+    &CheckFormElement($cache, 'SortProblems', 'SortProblems', 
+                      'Sort Within Sequence');
+
+    # Search only form elements
+    my @headingColumns=();
+    my @sequenceColumns=();
+    my $foundColumn = 0;
+    if(defined($ENV{'form.ReselectColumns'})) {
+        my @reselected = (ref($ENV{'form.ReselectColumns'}) ? 
+                          @{$ENV{'form.ReselectColumns'}}
+                          : ($ENV{'form.ReselectColumns'}));
+        foreach (@reselected) {
+            if(/HeadingColumn/) {
+                push(@headingColumns, $_);
+                $foundColumn = 1;
+            } elsif(/SequenceColumn/) {
+                push(@sequenceColumns, $_);
+                $foundColumn = 1;
+            }
+        }
+    }
+
+    $cache->{'reportKey'} = 'false';
+    if($cache->{'reportSelected'} eq 'Analyze') {
+        $cache->{'reportKey'} = 'Analyze';
+    } elsif($cache->{'reportSelected'} eq 'DoDiffGraph') {
+        $cache->{'reportKey'} = 'DoDiffGraph';
+    } elsif($cache->{'reportSelected'} eq 'PercentWrongGraph') {
+        $cache->{'reportKey'} = 'PercentWrongGraph';
+    }
+
+    if(defined($ENV{'form.DoDiffGraph'})) {
+        $cache->{'reportSelected'} = 'DoDiffGraph';
+        $cache->{'reportKey'} = 'DoDiffGraph';
+    } elsif(defined($ENV{'form.PercentWrongGraph'})) {
+        $cache->{'reportSelected'} = 'PercentWrongGraph';
+        $cache->{'reportKey'} = 'PercentWrongGraph';
+    }
+
+    foreach (keys(%ENV)) {
+        if(/form\.Analyze/) {
+            $cache->{'reportSelected'} = 'Analyze';
+            $cache->{'reportKey'} = 'Analyze';
+            my $data;
+            (undef, $data)=split(':::', $_);
+            $cache->{'AnalyzeInfo'}=$data;
+        } elsif(/form\.HeadingColumn/) {
+            my $value = $_;
+            $value =~ s/form\.//;
+            push(@headingColumns, $value);
+            $foundColumn=1;
+        } elsif(/form\.SequenceColumn/) {
+            my $value = $_;
+            $value =~ s/form\.//;
+            push(@sequenceColumns, $value);
+            $foundColumn=1;
+        }
+    }
+
+    if($foundColumn) {
+        $cache->{'HeadingsFound'} = join(':', @headingColumns);
+        $cache->{'SequencesFound'} = join(':', @sequenceColumns);;
+    }
+    if(!defined($cache->{'HeadingsFound'}) || 
+       $cache->{'DefaultColumns'} ne 'false') {
+        $cache->{'HeadingsFound'}='HeadingColumnFull Name';
+    }
+    if(!defined($cache->{'SequencesFound'}) ||
+       $cache->{'DefaultColumns'} ne 'false') {
+        $cache->{'SequencesFound'}='All Sequences';
     }
+    $cache->{'DefaultColumns'} = 'false';
 
     return;
 }
@@ -1394,419 +225,383 @@ Output: \@order
 =cut
 
 sub SortStudents {
-    my ($students,$cache)=@_;
+    my ($cache)=@_;
 
+    my @students = split(':::',$cache->{'NamesOfStudents'});
     my @sorted1Students=();
-    foreach (@$students) {
-        push(@sorted1Students, $_);
-    }
-#        my ($end,$start)=split(/\:/,$cache->{$_.':date'});
-#        my $active=1;
-#        my $now=time;
-#        my $Status=$cache->{'form.Status'};
-#        $Status = ($Status) ? $Status : 'Active';
-#        if((($end) && $now > $end) && (($Status eq 'Active'))) { 
-#            $active=0; 
-#        }
-#        if(($Status eq 'Expired') && ($end == 0 || $now < $end)) {
-#            $active=0;
-#        }
-#        if($active) {
-#            push(@sorted1Students, $_);
-#        }
-#    }
-
-    my $Pos = $cache->{'form.ChartSort'};
-    my %sortData;
-    if($Pos eq 'Last Name') {
-	for(my $index=0; $index<scalar @sorted1Students; $index++) {
-	    $sortData{$cache->{$sorted1Students[$index].':fullname'}}=
-		$sorted1Students[$index];
-	}
-    } elsif($Pos eq 'Section') {
-	for(my $index=0; $index<scalar @sorted1Students; $index++) {
-	    $sortData{$cache->{$sorted1Students[$index].':section'}.
-		      $sorted1Students[$index]}=$sorted1Students[$index];
-	}
-    } else {
-	# Sort by user name
-	for(my $index=0; $index<scalar @sorted1Students; $index++) {
-	    $sortData{$sorted1Students[$index]}=$sorted1Students[$index];
-	}
+    foreach (@students) {
+        if($cache->{'Status'} eq 'Any' || 
+           $cache->{$_.':Status'} eq $cache->{'Status'}) {
+            push(@sorted1Students, $_);
+        }
     }
 
-    my @order = ();
-    foreach my $key (sort(keys(%sortData))) {
-	push (@order,$sortData{$key});
+    my $sortBy = '';
+    if(defined($cache->{'sort'})) {
+        $sortBy = ':'.$cache->{'sort'};
     }
+    my @order = sort { $cache->{$a.$sortBy} cmp $cache->{$b.$sortBy} ||
+                       $cache->{$a.':fullname'} cmp $cache->{$b.':fullname'} } 
+                @sorted1Students;
 
     return \@order;
 }
 
+=pod
+
+=item &SpaceColumns()
+
+Determines the width of all the columns in the chart.  It is based on
+the max of the data for that column and its header.
+
+=over 4
+
+Input: $students, $studentInformation, $headings, $ChartDB
+
+$students: An array pointer to a list of students (username:domain)
+
+$studentInformatin: The type of data for the student information.  It is
+used as part of the key in $CacheData.
+
+$headings: The name of the student information columns.
+
+$ChartDB: The name of the cache database which is opened for read/write.
+
+Output: None - All data stored in cache.
+
+=back
+
+=cut
+
+sub SpaceColumns {
+    my ($students,$studentInformation,$headings,$cache)=@_;
+
+    # Initialize Lengths
+    for(my $index=0; $index<(scalar @$headings); $index++) {
+        my @titleLength=split(//,$headings->[$index]);
+        $cache->{$studentInformation->[$index].':columnWidth'}=
+            scalar @titleLength;
+    }
+
+    foreach my $name (@$students) {
+        foreach (@$studentInformation) {
+            my @dataLength=split(//,$cache->{$name.':'.$_});
+            my $length=(scalar @dataLength);
+            if($length > $cache->{$_.':columnWidth'}) {
+                $cache->{$_.':columnWidth'}=$length;
+            }
+        }
+    }
+
+    return;
+}
+
 sub PrepareData {
-    my ($c, $cacheDB)=@_;
+    my ($c, $cacheDB, $studentInformation, $headings,$r)=@_;
 
     # Test for access to the cache data
-    my $isCached=0;
     my $courseID=$ENV{'request.course.id'};
     my $isRecalculate=0;
-    if(defined($ENV{'form.ProblemStatisticsRecalculate'}) ||
-       defined($ENV{'form.ChartRecalculate'})) {
+    if(defined($ENV{'form.Recalculate'})) {
         $isRecalculate=1;
     }
 
-    $isRecalculate=1;
-
-    $isCached=&Apache::loncoursedata::TestCacheData($cacheDB, $isRecalculate);
+    my $isCached = &Apache::loncoursedata::TestCacheData($cacheDB, 
+                                                         $isRecalculate);
     if($isCached < 0) {
         return "Unable to tie hash to db file.";
     }
-    &ProcessFormData($cacheDB, $isCached);
 
     # Download class list information if not using cached data
     my %cache;
-    my @students=();
-    if(!$isCached) {
-        unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT,0640)) {
-            return "Unable to tie hash to db file.";
-        }
+    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
+        return "Unable to tie hash to db file.";
+    }
 
+    if(!$isCached) {
         my $processTopResourceMapReturn=
-            &Apache::loncoursedata::ProcessTopResourceMap(\%cache, $c);
+            &Apache::loncoursedata::ProcessTopResourceMap(\%cache, $c, $r);
         if($processTopResourceMapReturn ne 'OK') {
             untie(%cache);
             return $processTopResourceMapReturn;
         }
+    }
 
-        if($c->aborted()) {
-            untie(%cache);
-            return 'aborted'; 
-        }
+    if($c->aborted()) {
+        untie(%cache);
+        return 'aborted'; 
+    }
 
-        my $classlist=&Apache::loncoursedata::DownloadStudentNamePIDSection(
-                                                                   $courseID, 
-                                                                   $c);
-        my ($checkForError)=keys(%$classlist);
-        if($checkForError =~ /^(con_lost|error|no_such_host)/i ||
-           defined($classlist->{'error'})) {
+    my $classlist=&Apache::loncoursedata::DownloadClasslist($courseID,
+                                                $cache{'ClasslistTimestamp'},
+                                                $c);
+    foreach (keys(%$classlist)) {
+        if(/^(con_lost|error|no_such_host)/i) {
             untie(%cache);
             return "Error getting student data.";
         }
+    }
 
-        if($c->aborted()) {
-            untie(%cache);
-            return 'aborted'; 
-        }
+    if($c->aborted()) {
+        untie(%cache);
+        return 'aborted'; 
+    }
 
-        # Active is a temporary solution, remember to change
-        @students=&Apache::loncoursedata::ProcessClassList(\%cache, 
-                                                           $classlist, 
-                                                           $courseID, 
-                                                           'Active', $c);
+    # Active is a temporary solution, remember to change
+    Apache::loncoursedata::ProcessClasslist(\%cache,$classlist,$courseID,$c);
+    if($c->aborted()) {
+        untie(%cache);
+        return 'aborted'; 
+    }
 
-        if($c->aborted()) {
+    &ProcessFormData(\%cache);
+    my $students = &SortStudents(\%cache);
+    &SpaceColumns($students, $studentInformation, $headings, \%cache);
+    $cache{'updateTime:columnWidth'}=24;
+
+    if($cache{'download'} ne 'false') {
+        my @who = ($cache{'download'});
+        $cache{'download'} = 'false';
+        if(&Apache::loncoursedata::DownloadStudentCourseData(\@who, 'false', 
+                                                             $cacheDB, 'true', 
+                                                             'false', $courseID,
+                                                             $r, $c) ne 'OK') {
             untie(%cache);
-            return 'aborted'; 
+            return 'Stop at download individual';
         }
-
-        untie(%cache);
-    } else {
-        if(!$c->aborted() && tie(%cache,'GDBM_File',$cacheDB,
-                                 &GDBM_READER,0640)) {
-            @students=split(/:::/,$cache{'NamesOfStudents'});
+    } elsif($cache{'DownloadAll'} ne 'false') {
+        $cache{'DownloadAll'} = 'false';
+        my @allStudents;
+        if($cache{'DownloadAll'} eq 'sorted') {
+            @allStudents = @$students;
         } else {
-            return 'aborted';
+            @allStudents = split(':::', $cache{'NamesOfStudents'});
+        }
+        if(&Apache::loncoursedata::DownloadStudentCourseData(\@allStudents, 
+                                                             'false', 
+                                                             $cacheDB, 'true', 
+                                                             'true', $courseID,
+                                                             $r, $c) ne 'OK') {
+            untie(%cache);
+            return 'Stop at download all';
         }
     }
 
-    return ('OK', $isCached, \@students);
-}
-
-# Create progress
-sub Create_PrgWin {
-    $r->print(<<ENDPOP);
-    <script>
-    popwin=open('','popwin','width=400,height=100');
-    popwin.document.writeln('<html><body bgcolor="#88DDFF">'+
-      '<title>LON-CAPA Statistics</title>'+
-      '<h4>Computation Progress</h4>'+
-      '<form name=popremain>'+
-      '<input type=text size=35 name=remaining value=Starting></form>'+
-      '</body></html>');
-    popwin.document.close();
-    </script>
-ENDPOP
-
-    $r->rflush();
-}
-
-# update progress
-sub Update_PrgWin {
-    my ($totalStudents,$index,$name)=@_;
-    $r->print('<script>popwin.document.popremain.remaining.value="'.
-              'Computing '.$index.'/'.$totalStudents.': '.
-              $name.'";</script>');
-    $r->rflush();
-}
-
-# close Progress Line
-sub Close_PrgWin {
-    $r->print('<script>popwin.close()</script>');
-    $r->rflush(); 
-}
-
-# For loading the colored table for display or un-colored for print
-sub setbgcolor {
-    my $PrintTable=shift;
-    undef %color;
-    if ($PrintTable){
-	$color{"gb"}="#FFFFFF";
-	$color{"red"}="#FFFFFF";
-	$color{"yellow"}="#FFFFFF";
-	$color{"green"}="#FFFFFF";
-	$color{"purple"}="#FFFFFF";
-    } else {
-	$color{"gb"}="#DDFFFF";
-	$color{"red"}="#FFDDDD";
-	$color{"yellow"}="#EEFFCC";
-	$color{"green"}="#DDFFDD";
-	$color{"purple"}="#FFDDFF";
-    }
-
-    return;
-}
-
-sub initial {
-    undef %hash;
-    undef %CachData;
-    undef %GraphDat;
-    undef %ConceptData;
-    undef $Pos;
-    undef $GData;
-}
-
-#---- END HELPER FUNCTIONS ---------------------------------------------------
-
-sub BuildProblemStatisticsPage {
-    my ($cacheDB, $students)=@_;
-
-    my %cache;
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return;
+    if($c->aborted()) {
+        untie(%cache);
+        return 'aborted'; 
     }
 
-    my $Ptr = '';
-    $Ptr .= '<form name="ProblemStatisticsPage" method="post" ';
-    $Ptr .= 'action="/adm/statistics">'."\n";
-    $Ptr .= '<table border="0"><tbody>';
-    $Ptr .= '<tr><td></td><td align="left"><input type="submit" name="Menu" ';
-    $Ptr .= 'value="Return to Menu" /></td></tr>'."\n";
-    $r->print($Ptr);
-
-    $r->print(&MapOptions(\%cache, 'ProblemStatistics'));
-    $r->print(&StatusOptions());
-    $r->print(&AscendOrderOptions());
-    $r->print(&ProblemStatisticsButtons(\%cache));
-    $r->print('</table>');
-
-    $r->print(&ProblemStatisticsLegend());
-
-#    my $discriminantFactor;
-#    my $list;
-#    foreach (@$students) {
-#        ($discriminantFactor, $list) = &ExtractStudentData($_);
-#    }
-
-#    my ($upper, $lower) = &Discriminant($discriminantFactor);
-#    my %Header = (0,"Homework Sets Order",1,"#Stdnts",2,"Tries",3,"Mod",
-#                  4,"Mean",5,"#YES",6,"#yes",7,"%Wrng",8,"DoDiff",
-#                  9,"S.D.",10,"Skew.",11,"D.F.1st",12,"D.F.2nd");
-#    &BuildStatisticsTable(\%cache, $discriminantFactor, $list, \%Header);
-
-    $r->print('</form>');
-
     untie(%cache);
 
-    return;
+    return ('OK', $students);
 }
 
-sub BuildDiffGraph {
-    my ($courseID)=@_;
-
-    my $graphData = &GetGraphData('DiffGraph', $courseID);
-    $r->print('<IMG src="/cgi-bin/graph.gif?'.$graphData.'" />');
-
-    return;
-}
-
-sub BuildWrongGraph {
-    my ($courseID)=@_;
-
-    my $graphData = &GetGraphData('WrongGraph', $courseID);
-    $r->print('<IMG src="/cgi-bin/graph.gif?'.$graphData.'" />');
-
-    return;
-}
-
-sub BuildAnalyzePage {
-    my ($cacheDB, $students, $courseID)=@_;
+sub BuildClasslist {
+    my ($cacheDB,$students,$studentInformation,$headings,$r)=@_;
 
     my %cache;
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return;
+    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
+        return '<html><body>Unable to tie database.</body></html>';
     }
 
-    &ShowOpGraph(\%cache, $students, $courseID);
-
-    untie(%cache);
-
-    return;
-}
+    my $Str='';
+    $Str .= '<table border="0"><tr><td bgcolor="#777777">'."\n";
+    $Str .= '<table border="0" cellpadding="3"><tr bgcolor="#e6ffff">'."\n";
+
+    my $displayString = '<td align="left"><a href="/adm/statistics?';
+    $displayString .= 'sort=LINKDATA">DISPLAYDATA&nbsp</a></td>'."\n";
+    $Str .= &Apache::lonhtmlcommon::CreateHeadings(\%cache, 
+                                                   $studentInformation,
+                                                   $headings, $displayString);
+    $Str .= '</tr>'."\n";
 
-sub BuildProblemAnalysisPage {
-    my ($cacheDB)=@_;
+    my $alternate=0;
+    foreach (@$students) {
+        my ($username, $domain) = split(':', $_);
+        if($alternate) {
+            $Str .= '<tr bgcolor="#ffffe6">';
+        } else {
+            $Str .= '<tr bgcolor="#ffffc6">';
+        }
+        $alternate = ($alternate + 1) % 2;
+        foreach my $data (@$studentInformation) {
+            $Str .= '<td>';
+            if($data eq 'fullname') {
+                $Str .= '<a href="/adm/statistics?reportSelected=';
+                $Str .= &Apache::lonnet::escape('Student Assessment');
+                $Str .= '&StudentAssessmentStudent=';
+                $Str .= &Apache::lonnet::escape($cache{$_.':'.$data}).'">';
+                $Str .= $cache{$_.':'.$data}.'&nbsp';
+                $Str .= '</a>';
+            } elsif($data eq 'updateTime') {
+                $Str .= '<a href="/adm/statistics?reportSelected=';
+                $Str .= &Apache::lonnet::escape('Class list');
+                $Str .= '&download='.$_.'">';
+                $Str .= $cache{$_.':'.$data}.'&nbsp';
+                $Str .= '&nbsp</a>';
+            } else {
+                $Str .= $cache{$_.':'.$data}.'&nbsp';
+            }
 
-    my %cache;
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return;
+            $Str .= '</td>'."\n";
+        }
     }
 
-    $r->print('<form name="ProblemAnalysisPage" method="post" ');
-    $r->print('action="/adm/statistics">'."\n");
-    $r->print('<tr><td></td><td align="left"><input type="submit" ');
-    $r->print('name="Menu" value="Return to Menu" /></td></tr>'."\n");
-    $r->print(&IntervalOptions());
-    $r->print(&OptionResponseTable(\%cache));
-    $r->print('</form>'."\n");
+    $Str .= '</tr>'."\n";
+    $Str .= '</table></td></tr></table>'."\n";
+    $r->print($Str);
+    $r->rflush();
 
     untie(%cache);
 
     return;
 }
 
-sub BuildStudentAssessmentPage {
-    my ($cacheDB, $students, $courseID)=@_;
+sub CreateMainMenu {
+    my ($status, $reports)=@_;
 
-    my %cache;
+    my $Str = '';
 
-    my $Ptr = '';
-    $Ptr .= '<form name="StudentAssessmentPage" method="post" ';
-    $Ptr .= 'action="/adm/statistics">'."\n";
-    $Ptr .= '<table border="0"><tbody>';
-    $Ptr .= '<tr><td></td><td align="left"><input type="submit" name="Menu" ';
-    $Ptr .= 'value="Return to Menu" /></td></tr>'."\n";
-    $r->print($Ptr);
+    $Str .= '<table border="0"><tbody><tr>'."\n";
+    $Str .= '<td></td><td></td>'."\n";
+    $Str .= '<td align="center"><b>Analysis Reports:</b></td>'."\n";
+    $Str .= '<td align="center"><b>Student Status:</b></td></tr>'."\n";
+    $Str .= '<tr>'."\n";
+    $Str .= '<td align="center"><input type="submit" name="Refresh" ';
+    $Str .= 'value="Refresh" /></td>'."\n";
+    $Str .= '<td align="center"><input type="submit" name="DownloadAll" ';
+    $Str .= 'value="Update All Student Data" /></td>'."\n";
+    $Str .= '<td align="center">';
+    $Str .= '<select name="reportSelected" onchange="document.';
+    $Str .= 'Statistics.submit()">'."\n";
+
+    foreach (sort(keys(%$reports))) {
+        next if($_ eq 'reportSelected');
+        $Str .= '<option name="'.$_.'"';
+        if($reports->{'reportSelected'} eq $reports->{$_}) {
+            $Str .= ' selected=""';
+        }
+        $Str .= '>'.$reports->{$_}.'</option>'."\n";
+    }
+    $Str .= '</select></td>'."\n";
+
+    $Str .= '<td align="center">';
+    $Str .= &Apache::lonhtmlcommon::StatusOptions($status, 'Statistics');
+    $Str .= '</td>'."\n";
 
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return;
-    }
+    $Str .= '</tr></tbody></table>'."\n";
+    $Str .= '<hr>'."\n";
 
-    my $selectedName = $cache{'StudentAssessmentStudent'};
-    for(my $index=0; $index<(scalar @$students); $index++) {
-        my ($username) = split(':', $students->[$index]);
-        if($username eq $selectedName) {
-            if($cache{'StudentAssessmentMove'} eq 'next') {
-                if($index == ((scalar @$students) - 1)) {
-                    ($selectedName) = split(':',$students->[0]);
-                } else {
-                    ($selectedName) = split(':',$students->[$index+1]);
-                }
-            } elsif($cache{'StudentAssessmentMove'} eq 'previous') {
-                if($index == 0) {
-                    ($selectedName) = split(':',
-                                           $students->[(scalar @$students)-1]);
-                } else {
-                    ($selectedName)=split(':',$students->[$index-1]);
-                }
-            }
-            last;
-        }
-    }
+    return $Str;
+}
 
-    $r->print(&MapOptions(\%cache, 'StudentAssessment'));
-    $r->print(&StudentOptions($students, $selectedName));
+sub BuildStatistics {
+    my ($r)=@_;
 
-    $Ptr  = '<tr><td></td><td align="left">';
-    $Ptr .= '<input type="submit" name="CreateStudentAssessment" ';
-    $Ptr .= 'value="Create Student Report" />';
-    $Ptr .= '&nbsp&nbsp&nbsp';
-    $Ptr .= '<input type="submit" name="PreviousStudent" ';
-    $Ptr .= 'value="Previous Student" />';
-    $Ptr .= '&nbsp&nbsp&nbsp';
-    $Ptr .= '<input type="submit" name="NextStudent" ';
-    $Ptr .= 'value="Next Student" />';
-    $Ptr .= '&nbsp&nbsp&nbsp';
-    $Ptr .= '</td></tr></tbody></table></form>'."\n";
-    $r->print($Ptr);
+    my $c = $r->connection;
+    my @studentInformation=('fullname','section','id','domain','username',
+                            'updateTime');
+    my @headings=('Full Name', 'Section', 'PID', 'Domain', 'User Name',
+                  'Last Updated');
+    my $spacing = '   ';
+    my %reports = ('classlist'          => 'Class list',
+                   'problem_statistics' => 'Problem Statistics',
+                   'student_assessment' => 'Student Assessment',
+#                   'activitylog'        => 'Activity Log',
+                   'reportSelected'     => 'Class list');
 
-    untie(%cache);
+    my %cache;
+    my $courseID=$ENV{'request.course.id'};
+    my $cacheDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
+                  "_$ENV{'user.domain'}_$courseID\_statistics.db";
 
-    if($selectedName eq 'No Student Selected') {
-	$r->print('<h3><font color=blue>WARNING: ');
-        $r->print('Please select a student</font></h3>');
-        return;
-    }
+    $r->print(&Apache::lonhtmlcommon::Title('LON-CAPA Statistics'));
 
-    my $name = '';
-    foreach (@$students) {
-        my ($currentName) = split(':',$_);
-        if($currentName eq $selectedName) {
-            $name = $_;
-            last;
-        }
+    my ($returnValue, $students) = &PrepareData($c, $cacheDB, 
+                                                \@studentInformation, 
+                                                \@headings,$r);
+    if($returnValue ne 'OK') {
+        $r->print($returnValue."\n".'</body></html>');
+        return OK;
     }
-    if($name eq '') {
-        $r->print('<h3><font color=blue>ERROR: Unknown student selected.');
-        $r->print('</font></h3>');
-        return;
+    if(!$c->aborted()) {
+        &Apache::loncoursedata::CheckForResidualDownload($cacheDB, 
+                                                         'true', 'true',
+                                                         $courseID,
+                                                         $r, $c);
     }
 
-    my $courseData = 
-        &Apache::loncoursedata::DownloadStudentCourseInformation($name, 
-                                                                 $courseID);
-    if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT,0640)) {
-        &Apache::loncoursedata::ProcessStudentData(\%cache, 
-                                                   $courseData, $name);
+    my $GoToPage;
+    if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
+        $GoToPage = $cache{'reportSelected'};
+        $reports{'reportSelected'} = $cache{'reportSelected'};
+        if(defined($cache{'reportKey'}) && 
+           !exists($reports{$cache{'reportKey'}}) && 
+           $cache{'reportKey'} ne 'false') {
+            $reports{$cache{'reportKey'}} = $cache{'reportSelected'};
+        }
+
+        if(defined($cache{'OptionResponses'})) {
+            $reports{'problem_analysis'} = 'Problem Analysis';
+        }
+
+        $r->print('<form name="Statistics" ');
+        $r->print('method="post" action="/adm/statistics">');
+        $r->print(&CreateMainMenu($cache{'Status'}, \%reports));
+        $r->rflush();
         untie(%cache);
+    } else {
+        $r->print('<html><body>Unable to tie database.</body></html>');
+        return OK;
     }
 
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $Ptr .= 'Could not tie database.';
-        return $Ptr;
-    }
-    $r->print(&StudentReport(\%cache, $name));
-    untie(%cache);
-
-    return;
-}
-
-sub BuildMenu {
-    my ($cacheDB)=@_;
-
-    my %cache;
-    unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return;
+    if($GoToPage eq 'Activity Log') {
+        &Apache::lonproblemstatistics::Activity();
+    } elsif($GoToPage eq 'Problem Statistics') {
+        &Apache::lonproblemstatistics::BuildProblemStatisticsPage($cacheDB, 
+                                                                  $students, 
+                                                                  $courseID, 
+                                                                  $c,$r);
+    } elsif($GoToPage eq 'Problem Analysis') {
+        &Apache::lonproblemanalysis::BuildProblemAnalysisPage($cacheDB, $r);
+    } elsif($GoToPage eq 'Student Assessment') {
+        &Apache::lonstudentassessment::BuildStudentAssessmentPage($cacheDB,
+                                                          $students,
+                                                          $courseID,
+                                                          'Statistics',
+                                                          \@headings,
+                                                          $spacing,
+                                                          \@studentInformation,
+                                                          $r, $c);
+    } elsif($GoToPage eq 'Analyze') {
+        &Apache::lonproblemanalysis::BuildAnalyzePage($cacheDB, $students, 
+                                                      $courseID, $r);
+    } elsif($GoToPage eq 'DoDiffGraph' || $GoToPage eq 'PercentWrongGraph') {
+        my $courseDescription = $ENV{'course.'.$courseID.'.description'};
+        $courseDescription =~ s/\ /"_"/eg;
+        &Apache::lonproblemstatistics::BuildGraphicChart($GoToPage, $cacheDB,
+                                                         $courseDescription,
+                                                         $students, $courseID,
+                                                         $r, $c);
+    } elsif($GoToPage eq 'Class list') {
+        &BuildClasslist($cacheDB, $students, \@studentInformation,
+                        \@headings, $r);
     }
 
-    $r->print('<form name="Menu" method="post" action="/adm/statistics" >');
-    $r->print(&CreateMenuForm(\%cache));
     $r->print('</form>'."\n");
+    $r->print("\n".'</body>'."\n".'</html>');
+    $r->rflush();
 
-    untie(%cache);
-
-    return;
+    return OK;
 }
 
 # ================================================================ Main Handler
 
 sub handler {
-    $r=shift;
-    &initial();
+    my $r=shift;
+
+#    $jr = $r;
 
     unless(&Apache::lonnet::allowed('vgr',$ENV{'request.course.id'})) {
         $ENV{'user.error.msg'}=
@@ -1835,63 +630,10 @@ sub handler {
     $r->content_type('text/html');
     $r->send_http_header;
 
-    my %cache;
-    my $courseID=$ENV{'request.course.id'};
-    my $cacheDB = "/home/httpd/perl/tmp/$ENV{'user.name'}".
-                  "_$ENV{'user.domain'}_$courseID\_statistics.db";
-    my $c = $r->connection;
-
-    my ($returnValue, $isCached, $students) = &PrepareData($c, $cacheDB);
-    if($returnValue ne 'OK') {
-        $r->print('<html><body>'.$returnValue."\n".'</body></html>');
-        return OK;
-    }
-
-    my $downloadTime=0;
-    my $GoToPage;
-    if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER,0640)) {
-        $students = &SortStudents($students, \%cache);
-        if(defined($cache{'time'})) {
-            $downloadTime=$cache{'time'};
-        } else {
-            $downloadTime=localtime();
-        }
-        if(!defined($cache{'GoToPage'})) {
-            $GoToPage = 'Menu';
-        } else {
-            $GoToPage = $cache{'GoToPage'};
-        }
-        untie(%cache);
-    } else {
-        $r->print('<html><body>Unable to tie database.</body></html>');
-        return OK;
-    }
-
-    &setbgcolor(0);
-    $r->print(&Title());
-
-    if($GoToPage eq 'ActivityLog') {
-        &Activity();
-    } elsif($GoToPage eq 'ProblemStatistics') {
-        &BuildProblemStatisticsPage($cacheDB, $students);
-    } elsif($GoToPage eq 'ProblemAnalysis') {
-        &BuildProblemAnalysisPage($cacheDB);
-    } elsif($GoToPage eq 'StudentAssessment') {
-        &BuildStudentAssessmentPage($cacheDB, $students, $courseID);
-    } elsif($GoToPage eq 'Analyze') {
-        &BuildAnalyzePage($cacheDB, $students, $courseID);
-    } elsif($GoToPage eq 'DoDiffGraph') {
-        &BuildDiffGraph($courseID);
-    } elsif($GoToPage eq 'PercentWrongGraph') {
-        &BuildWrongGraph($courseID);
-    } else {
-        &BuildMenu($cacheDB);
-    }
-
-    $r->print("\n".'</body>'."\n".'</html>');
-    $r->rflush();
+    &BuildStatistics($r);
 
     return OK;
 }
 1;
 __END__
+