# The LearningOnline Network with CAPA
#
# $Id: lonproblemanalysis.pm,v 1.108 2004/12/06 16:22:21 matthew Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
package Apache::lonproblemanalysis;

use strict;
use Apache::lonnet();
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::loncoursedata();
use Apache::lonstatistics;
use Apache::lonlocal;
use Apache::lonstathelpers();
use Apache::lonstudentsubmissions();
use HTML::Entities();
use Time::Local();
use Spreadsheet::WriteExcel();
use capa;

my $plotcolors = ['#33ff00', 
                  '#0033cc', '#990000', '#aaaa66', '#663399', '#ff9933',
                  '#66ccff', '#ff9999', '#cccc33', '#660000', '#33cc66',
                  ]; 

my @SubmitButtons = ({ name => 'PrevProblemAnalysis',
                       text => 'Previous Problem' },
                     { name => 'ProblemAnalysis',
                       text => 'Analyze Problem Again' },
                     { name => 'NextProblemAnalysis',
                       text => 'Next Problem' },
                     { name => 'break'},
                     { name => 'SelectAnother',
                       text => 'Choose a different Problem' },
                     { name => 'ExcelOutput',
                       text => 'Produce Excel Output' });

sub BuildProblemAnalysisPage {
    my ($r,$c)=@_;
    #
    my %Saveable_Parameters = ('Status' => 'scalar',
                               'Section' => 'array',
                               'NumPlots' => 'scalar',
                               'AnalyzeOver' => 'scalar',
                               );
    &Apache::loncommon::store_course_settings('problem_analysis',
                                              \%Saveable_Parameters);
    &Apache::loncommon::restore_course_settings('problem_analysis',
                                                \%Saveable_Parameters);
    #
    &Apache::lonstatistics::PrepareClasslist();
    #
    $r->print(&CreateInterface());
    #
    my @Students = @Apache::lonstatistics::Students;
    #
    if (@Students < 1 && exists($ENV{'form.firstrun'})) {
        $r->print('<h2>There are no students in the sections selected</h2>');
    }
    #
    my @CacheButtonHTML = 
        &Apache::lonstathelpers::manage_caches($r,'Statistics','stats_status');
    $r->rflush();
    #
    # Support for numerical and radio response isn't complete enough to
    # include in 1.2 release.
    my $problem_types = '(option|radiobutton|numerical)';
    # my $problem_types = '.';#(option)';
    if (exists($ENV{'form.problemchoice'}) && 
        ! exists($ENV{'form.SelectAnother'})) {
        foreach my $button (@SubmitButtons) {
            if ($button->{'name'} eq 'break') {
                $r->print("<br />\n");
            } else {
                $r->print('<input type="submit" name="'.$button->{'name'}.'" '.
                          'value="'.&mt($button->{'text'}).'" />');
                $r->print('&nbsp;'x5);
            }
        }
        foreach my $html (@CacheButtonHTML) {
            $r->print($html.('&nbsp;'x5));
        }
        #
        $r->print('<hr />');
        $r->rflush();
        #
        # Determine which problem we are to analyze
        my $current_problem = &Apache::lonstathelpers::get_target_from_id
            ($ENV{'form.problemchoice'});
        #
        my ($prev,$curr,$next) = 
            &Apache::lonstathelpers::get_prev_curr_next($current_problem,
                                                        $problem_types,
                                                        'response',
                                                        );
        if (exists($ENV{'form.PrevProblemAnalysis'}) && defined($prev)) {
            $current_problem = $prev;
        } elsif (exists($ENV{'form.NextProblemAnalysis'}) && defined($next)) {
            $current_problem = $next;
        } else {
            $current_problem = $curr;
        }
        #
        # Store the current problem choice and send it out in the form
        $ENV{'form.problemchoice'} = 
            &Apache::lonstathelpers::make_target_id($current_problem);
        $r->print('<input type="hidden" name="problemchoice" value="'.
                  $ENV{'form.problemchoice'}.'" />');
        #
        if (! defined($current_problem->{'resource'})) {
            $r->print('resource is undefined');
        } else {
            my $resource = $current_problem->{'resource'};
            $r->print('<h1>'.$resource->{'title'}.'</h1>');
            $r->print('<h3>'.$resource->{'src'}.'</h3>');
            if ($ENV{'form.show_prob'} eq 'true') {
                $r->print(&Apache::lonstathelpers::render_resource($resource));
            }
            $r->rflush();
            my %Data = &Apache::lonstathelpers::get_problem_data
                ($resource->{'src'});
            my $problem_data = $Data{$current_problem->{'part'}.
                                    '.'.
                                    $current_problem->{'respid'}};
            if ($current_problem->{'resptype'} eq 'option') {
                &OptionResponseAnalysis($r,$current_problem,
                                        $problem_data,
                                        \@Students);
            } elsif ($current_problem->{'resptype'} eq 'radiobutton') {
                &radio_response_analysis($r,$current_problem,
                                         $problem_data,
                                         \@Students);
            } elsif ($current_problem->{'resptype'} eq 'numerical') {
                &numerical_response_analysis($r,$current_problem,
                                             $problem_data,\@Students);
            } else {
                $r->print('<h2>Analysis of '.$current_problem->{'resptype'}.' is not supported</h2>');
            }
        }
        $r->print('<hr />');
    } else {
        $r->print('<input type="submit" name="ProblemAnalysis" value="'.
                  &mt('Analyze Problem').'" />');
        $r->print('&nbsp;'x5);
        $r->print('<h3>'.&mt('Please select a problem to analyze').'</h3>');
        $r->print(&Apache::lonstathelpers::ProblemSelector
                  ($problem_types));
    }
}

#########################################################
#########################################################
##
##      Numerical Response Routines
##
#########################################################
#########################################################
sub numerical_response_analysis {
    my ($r,$problem,$problem_analysis,$students) = @_;
    my $c = $r->connection();
    #
    if ($ENV{'form.AnalyzeOver'} !~ /^(tries|time)$/) {
        $r->print('Bad request');
    }
    #
    my ($resource,$partid,$respid) = ($problem->{'resource'},
                                      $problem->{'part'},
                                      $problem->{'respid'});
    # Gather student data
    my $response_data = &Apache::loncoursedata::get_response_data
        (\@Apache::lonstatistics::SelectedSections,
         $Apache::lonstatistics::enrollment_status,
         $resource->{'symb'},$respid);
    #
    $problem_analysis->{'answercomputed'} = 1;
    if ($problem_analysis->{'answercomputed'}) {
        my $answers = 
            &Apache::lonstathelpers::GetStudentAnswers($r,$problem,$students,
                                                       'Statistics',
                                                       'stats_status');
        $r->print(&numerical_one_dimensional_plot($r,600,150,$answers));
    }
    #
    if (ref($response_data) ne 'ARRAY') {
        $r->print('<h2>'.
                  &mt('There is no submission data for this resource').
                  '</h2>');
        return;
    }
    my $analysis_html = '<table>';
    for (my $plot_num = 1;$plot_num<=$ENV{'form.NumPlots'};$plot_num++) {
        my $restriction_function;
        my $header_message;
        my $stats_message;
        my $post_message; # passed through &mt sooner rather than later
        my $no_data_message;
        my @extra_data;
        if ($ENV{'form.AnalyzeOver'} eq 'tries') {
            $restriction_function = sub {($_[0]->{'tries'} == $plot_num?1:0)};
            $header_message = 'Attempt [_1]';
            $stats_message = 
                '[_1] submissions, [_2] correct, [_3] incorrect';
            $post_message = '';
            $no_data_message = 'No data exists for attempt [_1]';
        } else {
            my $starttime = &Apache::lonhtmlcommon::get_date_from_form
                ('startdate_'.$plot_num);
            my $endtime = &Apache::lonhtmlcommon::get_date_from_form
                ('enddate_'.$plot_num);
            ($starttime,$endtime) = &ensure_start_end_times
                ($starttime,$endtime,
                 &get_time_from_row($response_data->[0]),
                 &get_time_from_row($response_data->[-1]),
                 $plot_num);
            $header_message = 'Data from [_2] to [_3]';
            $extra_data[0] = &Apache::lonlocal::locallocaltime($starttime);
            $extra_data[1] = &Apache::lonlocal::locallocaltime($endtime);
            #
            $stats_message = 
                '[_1] submissions from [_4] students, [_2] correct, [_3] incorrect';
            #
            $post_message = 
                &mt('Start time: [_1]',
                    &Apache::lonhtmlcommon::date_setter
                    ('Statistics','startdate_'.$plot_num,$starttime)).
                '<br />'.
                &mt('End time: [_1]',
                    &Apache::lonhtmlcommon::date_setter
                    ('Statistics','enddate_'.$plot_num,$endtime));
            $restriction_function = 
                sub { 
                    my $t = $_[0]->{'timestamp'};
                    if ($t >= $starttime && $t < $endtime) {
                        return 1;
                    } else { 
                        return 0;
                    }
                };
            $no_data_message = 'No data for [_2] to [_3]';
        }
        #
        my ($correct,$answers) = 
            &numerical_determine_answers($r,$resource,$partid,
                                         $respid,$students);
        if ($c->aborted()) { return; };
        #
        my $responses = &numerical_classify_responses($response_data,$correct,
                                                      $restriction_function);
        if ($responses->{'_count'} == 0) {
            $analysis_html.= 
                '<tr><td colspan="2"><font size="+1"><b>'.
                &mt($no_data_message,$plot_num,@extra_data).
                '</b></font></td></tr>';
        } else {
            $analysis_html.= 
                '<tr><td colspan="2" align="center"><font size="+1"><b>'.
                &mt($header_message,$plot_num,@extra_data).
                '</b></font></td></tr>'.
                '<tr><td colspan="2" align="center">'.
                &mt($stats_message,
                    $responses->{'_count'},
                    $responses->{'_correct'},
                    $responses->{'_count'}-$responses->{'_correct'},
                    $responses->{'_students'},
                    @extra_data).
                    '</td></tr>'.
                    '<tr>'.'<td valign="top" align="center">'.
                    &numerical_plot_percent($r,$responses).'</td>'.
                    '<td align="center" valign="top">'.
                    &numerical_plot_differences($r,$responses).'</td>'.
                    '</tr>';
        }
        if ($post_message ne '') {
            $analysis_html .=
                '<tr><td colspan="2">'.$post_message.'</td></tr>';
        }
    }
    $analysis_html.='</table>';
    $r->print($analysis_html);
    #
    return;
}

sub numerical_plot_percent {
    my ($r,$responses) = @_;
    #
    my $total = $responses->{'_count'};
    return '' if ($total == 0);
    my $minbin = 5;
    while (my ($interval,$submissions) = each(%$responses)) {
        next if ($interval =~ /^_/);
        my ($ans,$ans_low,$ans_high) = split(" ",$interval);
        my $low_percent  = abs(100*($ans-$ans_low)/$ans);
        my $high_percent = abs(100*($ans_high-$ans)/$ans);
        if ($minbin > $high_percent) { $minbin = $high_percent; }
        if ($minbin > $low_percent) { $minbin = $low_percent; }
    }
    #
    my @bins;
    if ($minbin < 1) {
        @bins = ('0.1','0.5','1.0','1.5','2.0','2.5','3.0','4.0','5.0',10,20,50,100);        
    } elsif ($minbin < 2) {
        @bins = ('0.5','1.0','1.5','2.0','2.5','3.0','4.0','5.0',10,20,50,100);
    } elsif ($minbin < 5) {
        @bins = (1,2,3,4,5,10,25,50,75,100,200);
    } elsif ($minbin < 10) {
        @bins = (2,4,6,8,10,12,15,20,25,30,50,75,100,200);
    } else {
        @bins = (5,10,15,20,25,30,50,75,100,200);
    }
    my @labels = (1..scalar(@bins));
    #
    my @correct;
    my @incorrect;
    my @count;
    while (my ($interval,$submissions) = each(%$responses)) {
        next if ($interval =~ /^_/);
        my ($ans,$ans_low,$ans_high) = split(" ",$interval);
        while (my ($submission,$counts) = each(%$submissions)) {
            my ($correct_count,$incorrect_count) = @$counts;
            my $scaled_value = abs(($submission-$ans)/$ans);
            my $bin=0;
            for ($bin=0;$bin<$#bins;$bin++) { # not <= for a reason
                last if ($bins[$bin]>$scaled_value);
            }
            $correct[$bin]+=$correct_count;
            $incorrect[$bin]+=$incorrect_count;
            $count[$bin]+=$correct_count+$incorrect_count;
        }
    }
    #
    my @plot_correct;
    my @plot_incorrect;
    for (my $i=0;$i<=$#bins;$i++) {
        $plot_correct[$i] = $correct[$i]*100/$total;
        $plot_incorrect[$i] = $incorrect[$i]*100/$total;
    }
    my $title = &mt('Distribution by Percent');
    my $graph = &Apache::loncommon::DrawBarGraph
        ($title,'Percent difference from correct','Number of answers',
         100,['#33FF00','#FF3300'],\@labels,\@plot_correct,\@plot_incorrect,
         {xskip=>1});
    #
    my $table = $graph.$/.
        &numerical_bin_table(\@bins,\@labels,\@incorrect,\@correct,\@count).$/;
    return $table;
}

sub numerical_plot_differences {
    my ($r,$responses) = @_;
    #
    my $total = $responses->{'_count'};
    return '' if ($total == 0);
    my $minbin = undef;
    my $maxbin = undef;
    while (my ($interval,$submissions) = each(%$responses)) {
        next if ($interval =~ /^_/);
        my ($ans,$ans_low,$ans_high) = split(" ",$interval);
        my $low_diff  = abs($ans-$ans_low);
        my $high_diff = abs($ans_high-$ans);
        if (! defined($maxbin)) { $maxbin = $low_diff;}
        if (! defined($minbin)) { $minbin = $low_diff;}
        #
        if ($minbin > $high_diff) { $minbin = $high_diff; }
        if ($minbin > $low_diff ) { $minbin = $low_diff; }
        #
        if ($maxbin < $high_diff) { $maxbin = $high_diff; }
        if ($maxbin < $low_diff ) { $maxbin = $low_diff; }
    }    
    #
    my @bins;
    my @labels;
    # Hmmmm, should switch to absolute difference
    for (my $i=1;$i<=20;$i++) {
        push(@bins,$i*$minbin/2);
        push(@labels,$i);
    }
    #
    my @correct;
    my @incorrect;
    my @count;
    while (my ($interval,$submissions) = each(%$responses)) {
        next if ($interval =~ /^_/);
        my ($ans,$ans_low,$ans_high) = split(" ",$interval);
        while (my ($submission,$counts) = each(%$submissions)) {
            my ($correct_count,$incorrect_count) = @$counts;
            my $value = abs($submission-$ans);
            my $bin=0;
            for ($bin=0;$bin<$#bins;$bin++) { # not <= for a reason
                last if ($bins[$bin]>$value);
            }
            $correct[$bin]+=$correct_count;
            $incorrect[$bin]+=$incorrect_count;
            $count[$bin]+=$correct_count+$incorrect_count;
        }
    }
    #
    my @plot_correct;
    my @plot_incorrect;
    for (my $i=0;$i<=$#bins;$i++) {
        $plot_correct[$i]   =   $correct[$i]*100/$total;
        $plot_incorrect[$i] = $incorrect[$i]*100/$total;
    }
    my $title = &mt('Distribution by Magnitude');
    my $graph = &Apache::loncommon::DrawBarGraph
        ($title,'magnitude difference from correct','Number of answers',
         100,['#33FF00','#FF3300'],\@labels,\@plot_correct,\@plot_incorrect,
         {xskip=>1});
    #
    my $table = $graph.$/.
        &numerical_bin_table(\@bins,\@labels,\@incorrect,\@correct,\@count).$/;
    return $table;
}

sub numerical_classify_responses {
    &Apache::lonnet::logthis('--------------');
    my ($full_row_data,$correct,$function) = @_;
    my %submission_data;
    my %students;
    my $max=0;
    foreach my $row (@$full_row_data) {
#        &Apache::lonnet::logthis(' row = '.join(',',@$row));
        my %subm = &hashify_attempt($row);
        if (ref($correct) eq 'HASH') {
            $subm{'correct'} = $correct->{$subm{'student'}}->{'answer'};
            $subm{'unit'} = $correct->{$subm{'student'}}->{'unit'};
        } else { # This probably never happens....
            $subm{'correct'} = $correct->{'answer'};
            $subm{'unit'} = $correct->{'unit'};
        }
        $subm{'submission'} =~ s/=\d+\s*$//;
        if (&$function(\%subm)) {
            my $scaled = '1';
            my ($sname,$sdom) = split(':',$subm{'student'});
            # Note that $subm{'unit'} is modified by the following call
            # We do not use it again but you should be aware just in case.
#            my ($myunit,$mysub) = ($subm{'unit'},$subm{'submission'});
#            $myunit = 'm';
#            # &Apache::lonnet::logthis($myunit);
#            my $result = 
#                &capa::caparesponse_get_real_response($myunit,
#                                                      $mysub,
#                                                      \$scaled);
#            # &Apache::lonnet::logthis('  '.$myunit.':'.$subm{'unit'}.
#            #  ' '.$mysub.':'.$subm{'submission'}.'; '.$result);
#            next if (! defined($scaled));
#            next if ($result ne '6');
#            my $submission = $scaled;
            my $submission = $subm{'submission'};
            $students{$subm{'student'}}++;
            if (&numerical_submission_is_correct($subm{'award'})) { 
                &Apache::lonnet::logthis('correct:'.$submission.':'.$subm{'correct'});
                $submission_data{'_correct'}++;
                $submission_data{'_count'}++;
                $submission_data{$subm{'correct'}}->{$submission}->[0]++;
            } elsif (&numerical_submission_is_incorrect($subm{'award'})) { 
                &Apache::lonnet::logthis('incorrect:'.$submission.':'.$subm{'correct'});
                $submission_data{'_count'}++;
                $submission_data{$subm{'correct'}}->{$submission}->[1]++;
            }
            my $value = 
                $submission_data{$subm{'correct'}}->{$submission}->[0]+ 
                $submission_data{$subm{'correct'}}->{$submission}->[1];
            if ($max < $value) { $max = $value; }
        }
    }
    $submission_data{'_max'} = $max;
    $submission_data{'_students'}=scalar(keys(%students));
    return \%submission_data;
}

sub numerical_submission_is_correct {
    my ($award) = @_;
    &Apache::lonnet::logthis('award = "'.$award.'"');
    if ($award =~ /^(APPROX_ANS|EXACT_ANS)$/) {
        return 1;
    } else {
        return 0;
    }
}

sub numerical_submission_is_incorrect {
    my ($award) = @_;
    if ($award =~ /^(INCORRECT)$/) {
        return 1;
    } else {
        return 0;
    }
}

sub numerical_bin_table {
    my ($bins,$labels,$incorrect,$correct,$count)=@_;
    my $table = 
        '<table><tr><th>'.&mt('Bar').'</th>'.
        '<th colspan="3">'.&mt('Range').'</th>'.
        '<th>'.&mt('Incorrect').'</th>'.
        '<th>'.&mt('Correct').'</th>'.
        '<th>'.&mt('Count').'</th>'.
        '</tr>'.$/;
    for (my $i=0;$i<scalar(@{$bins});$i++) {
        my $lownum;
        if ($i == 0) {
            $lownum = 0;
        } else {
            $lownum = $bins->[$i-1];
        }
        my $highnum = $bins->[$i];
        $table .= 
            '<tr>'.
            '<td>'.$labels->[$i].'</td>'.
            '<td align="right">'.$lownum.'</td>'.
            '<td>&nbsp;-&nbsp;</td>'.
            '<td align="right">'.$highnum.'</td>'.
            '<td align="right">'.$incorrect->[$i].'</td>'.
            '<td align="right">'.$correct->[$i].'</td>'.
            '<td align="right">'.$count->[$i].'</td>'.
            '</tr>'.$/;
    }
    $table.= '</table>';
    return $table;
}

sub numerical_determine_answers {
    my ($r,$resource,$partid,$respid,$students)=@_;
    my $c = $r->connection();
    #
    # FIX ME: May need progress dialog updates
    #
    # Read in the cache (if it exists) before we start timing things.
    &Apache::lonstathelpers::ensure_proper_cache($resource->{'symb'});
    #
    my $correct;
    my %answers;
    foreach my $student (@$students) {
        last if ($c->aborted());
        my $sname = $student->{'username'};
        my $sdom = $student->{'domain'};
        # analyze problem
        my $analysis = 
            &Apache::lonstathelpers::analyze_problem_as_student($resource,
                                                                $sname,
                                                                $sdom);
        # make the key
        my $key = $partid.'.'.$respid;
        $correct->{$sname.':'.$sdom}->{'answer'} = 
            $analysis->{$key.'.answer'}->[0];
        $correct->{$sname.':'.$sdom}->{'unit'} = 
            $analysis->{$key.'.unit'}->[0];
        $answers{$analysis->{$key.'.answer'}->[0]}++;
    }
    &Apache::lonstathelpers::write_analysis_cache();
    return ($correct,\%answers);
}

#
# Inputs: $r, $width, $height, $data
#         $n = number of students
#         $data = hashref of $answer => $frequency pairs
sub numerical_one_dimensional_plot {
    my ($r,$width,$height,$data)=@_;
    #
    # Compute data -> image scaling factors
    my $max_y = 0;
    my $min_x = undef;
    my $max_x = undef;
    my $n = 0;
    while (my ($answer,$count) = each(%$data)) {
        $n+=$count;
        $max_y = $count if ($max_y < $count);
        if (! defined($min_x) || $answer < $min_x) {
            $min_x = $answer;
        }
        if (! defined($max_x) || $answer > $max_x) {
            $max_x = $answer;
        }
    }
    #
    my $min_max_difference = $max_x - $min_x;
    if (! defined($min_max_difference) || $min_max_difference == 0) {
        $min_max_difference = 1;
    }
    my $h_scale = ($width-10)/$min_max_difference;
    #
    my $ticscale = 5;
    if ($max_y * $ticscale > $height/2) {
        $ticscale = int($height/2/$max_y);
        $ticscale = 1 if ($ticscale < 1);
    }
    #
    # Create the plot
    my $plot = 
        qq{<drawimage width="$width" height="$height" bgcolor="transparent" >};
    while (my ($answer,$count) = each(%$data)) {
        my $xloc = 5+$h_scale*($answer - $min_x);
        my $top    = $height/2-$count*$ticscale;
        my $bottom = $height/2+$count*$ticscale;
        $plot .= &line($xloc,$top,$xloc,$bottom,'888888',1);
    }
    #
    # Put the scale on last to ensure it is on top of the data.
    if ($min_x < 0 && $max_x > 0) {
        my $circle_x = 5+$h_scale*abs($min_x);  # '0' in data coordinates
        my $r = 4;
        $plot .= &line(5,$height/2,$circle_x-$r,$height/2,'000000',1);
        $plot .= &circle($circle_x,$height/2,$r+1,'000000');
        $plot .= &line($circle_x+$r,$height/2,$width-5,$height/2,'000000',1);
    } else {
        $plot .= &line(5,$height/2,$width-5,$height/2,'000000',1);
    }
    $plot .= '</drawimage>';
    my $plotresult =  &Apache::lonxml::xmlparse($r,'web',$plot);
    my $result = '<table>'.
        '<tr><td colspan="3" align="center">'.
        '<font size="+2">'.&mt('Distribution of correct answers').'</font>'.
        '<br />'.&mt('[_1] students, [_2] distinct correct answers',
                     $n,scalar(keys(%$data))).
        '<br />'.&mt('Maximum number of coinciding values: [_1]',$max_y).
        '</td></tr>'.
        '<tr>'.
        '<td valign="center">'.$min_x.'</td>'.
        '<td>'.$plotresult.'</td>'.
        '<td valign="center">'.$max_x.'</td>'.
        '</tr>'.
        '</table>';
    return $result;
}

##
## Helper subroutines for <drawimage>.  
## These should probably go somewhere more suitable soon.
sub line {
    my ($x1,$y1,$x2,$y2,$color,$thickness) = @_;
    return qq{<line x1="$x1" y1="$y1" x2="$x2" y2="$y2" color="$color" thickness="$thickness" />};
}

sub text {
    my ($x,$y,$color,$text,$font,$direction) = @_;
    if (! defined($font) || $font !~ /^(tiny|small|medium|large|giant)$/) {
        $font = 'medium';
    }
    if (! defined($direction) || $direction ne 'vertical') {
        $direction = '';
    }
    return qq{<text x="$x" y="$y" color="$color" font="$font" direction="$direction" >$text</text>};
}

sub rectangle {
    my ($x1,$y1,$x2,$y2,$color,$thickness,$filled) = @_;
    return qq{<rectangle x1="$x1" y1="$y1" x2="$x2" y2="$y2" color="$color" thickness="$thickness" filled="$filled" />};
}

sub arc {
    my ($x,$y,$width,$height,$start,$end,$color,$thickness,$filled)=@_;
    return qq{<arc x="$x" y="$y" width="$width" height="$height" start="$start" end="$end" color="$color" thickness="$thickness" filled="$filled" />};
}

sub circle {
    my ($x,$y,$radius,$color,$thickness,$filled)=@_;
    return &arc($x,$y,$radius,$radius,0,360,$color,$thickness,$filled);
}

#########################################################
#########################################################
##
##      Radio Response Routines
##
#########################################################
#########################################################
sub radio_response_analysis {
    my ($r,$problem,$problem_analysis,$students) = @_;
    #
    if ($ENV{'form.AnalyzeOver'} !~ /^(tries|time)$/) {
        $r->print('Bad request');
    }
    #
    my ($resource,$partid,$respid) = ($problem->{'resource'},
                                      $problem->{'part'},
                                      $problem->{'respid'});
    #
    my $analysis_html;
    my $foildata = $problem_analysis->{'_Foils'};
    my ($table,$foils,$concepts) = &build_foil_index($problem_analysis);
    if (! defined($concepts)) {
        $concepts = [];
    }
    #
    my %true_foils;
    my $num_true = 0;
    if (! $problem_analysis->{'answercomputed'}) {
        foreach my $foil (@$foils) {
            if ($foildata->{$foil}->{'value'} eq 'true') {
                $true_foils{$foil}++; 
            }
        }
        $num_true = scalar(keys(%true_foils));
    }
    #
    $analysis_html .= $table;
    # Gather student data
    my $response_data = &Apache::loncoursedata::get_response_data
        (\@Apache::lonstatistics::SelectedSections,
         $Apache::lonstatistics::enrollment_status,
         $resource->{'symb'},$respid);
    my $correct;   # either a hash reference or a scalar
    if ($problem_analysis->{'answercomputed'} || scalar(@$concepts) > 1) {
        # This takes a while for large classes...
        &Apache::lonstathelpers::GetStudentAnswers($r,$problem,$students,
                                                   'Statistics',
                                                   'stats_status');
        foreach my $student (@$students) {
            my ($idx,@remainder) = split('&',$student->{'answer'});
            my ($answer) = ($remainder[$idx]=~/^(.*)=([^=]*)$/);
            $correct->{$student->{'username'}.':'.$student->{'domain'}}=
                &Apache::lonnet::unescape($answer);
        }
    } else {
        foreach my $foil (keys(%$foildata)) {
            if ($foildata->{$foil}->{'value'} eq 'true') {
                $correct = $foildata->{$foil}->{'name'};
            }
        }
    }
    #
    if (! defined($response_data) || ref($response_data) ne 'ARRAY' ) {
        $analysis_html = '<h2>'.
            &mt('There is no submission data for this resource').
            '</h2>';
        $r->print($analysis_html);
        return;
    }
    #
    $analysis_html.='<table>';
    for (my $plot_num = 1;$plot_num<=$ENV{'form.NumPlots'};$plot_num++) {
        # classify data ->correct foil -> selected foil
        my ($restriction_function,
            $correct_foil_title,$incorrect_foil_title,
            $pre_graph_text,$post_graph_text,
            $no_data_text,@extra_data);
        if ($ENV{'form.AnalyzeOver'} eq 'tries') {
            $restriction_function = sub {($_[0]->{'tries'} == $plot_num?1:0)};
            $correct_foil_title = 'Attempt '.$plot_num;
            $incorrect_foil_title = 'Attempt '.$plot_num;
            $pre_graph_text = 
                'Attempt [_1], [_2] submissions, [_3] correct, [_4] incorrect';
            $post_graph_text = '';
            $no_data_text = 'No data exists for attempt [_1]';
        } elsif ($ENV{'form.AnalyzeOver'} eq 'time') {
            my $starttime = &Apache::lonhtmlcommon::get_date_from_form
                ('startdate_'.$plot_num);
            my $endtime = &Apache::lonhtmlcommon::get_date_from_form
                ('enddate_'.$plot_num);
            ($starttime,$endtime) = &ensure_start_end_times
                ($starttime,$endtime,
                 &get_time_from_row($response_data->[0]),
                 &get_time_from_row($response_data->[-1]),
                 $plot_num);
            $pre_graph_text = 
                'Data from [_6] to [_7]<br /> [_2] submissions from [_5] students, [_3] correct, [_4] incorrect';
            $extra_data[0] = &Apache::lonlocal::locallocaltime($starttime);
            $extra_data[1] = &Apache::lonlocal::locallocaltime($endtime);
            #
            $post_graph_text = 
                &mt('Start time: [_1]',
                    &Apache::lonhtmlcommon::date_setter
                    ('Statistics','startdate_'.$plot_num,$starttime)).
                '<br />'.
                &mt('End time: [_1]',
                    &Apache::lonhtmlcommon::date_setter
                    ('Statistics','enddate_'.$plot_num,$endtime));
            $restriction_function = 
                sub { 
                    my $t = $_[0]->{'timestamp'};
                    if ($t >= $starttime && $t < $endtime) {
                        return 1;
                    } else { 
                        return 0;
                    }
                };
            $no_data_text = 'No data for [_5] to [_6]';
        }
        my $foil_choice_data =
            &classify_response_data($response_data,$correct,
                                    $restriction_function);
        # &Apache::lonstathelpers::log_hash_ref($foil_choice_data);
        my $answers;
        if (ref($correct)) {
            my %tmp;
            foreach my $foil (values(%$correct)) {
                $tmp{$foil}++;
            }
            $answers = [keys(%tmp)];
        } else {
            $answers = [$correct];
        }
        # Concept Plot
        my $concept_plot = '';
        if (scalar(@$concepts) > 1) {
            $concept_plot = &RR_concept_plot($concepts,$foil_choice_data,
                                             'Correct Concepts');
        }
        # % Choosing plot
        my $choice_plot = &RR_create_percent_selected_plot
            ($concepts,$foils,$foil_choice_data,$correct_foil_title);
        # for each correct foil, how did they mark it? (stacked bar graph)
        my ($stacked_plot,$count_by_foil);
        if ($problem_analysis->{'answercomputed'} || $num_true > 1) {
            ($stacked_plot,$count_by_foil) =
                &RR_create_stacked_selection_plot($foils,$foil_choice_data,
                                                  $incorrect_foil_title,
                                                  \%true_foils);
        }
        #
        if ($concept_plot ne '' ||
            $choice_plot  ne '' ||
            $stacked_plot ne '') {
            my $correct = $foil_choice_data->{'_correct'};
            if (! defined($correct) || $correct eq '') {
                $correct = 0;
            }
            my $incorrect = 
            $analysis_html.= '<tr><td colspan="4" align="center">'.
                '<font size="+1">'.
                &mt($pre_graph_text,
                    $plot_num,$foil_choice_data->{'_count'},
                    $correct,
                    $foil_choice_data->{'_count'}-$correct,
                    $foil_choice_data->{'_students'},
                    @extra_data).
                    '</td></tr>'.$/;
            $analysis_html.=
                '<tr>'.
                '<td>'.$concept_plot.'</td>'.
                '<td>'.$choice_plot.'</td>';
            if ($stacked_plot ne '') {
                $analysis_html .= 
                    '<td>'.$stacked_plot.'</td>'.
                    '<td>'.&build_foil_key($foils,$count_by_foil).'</td>';
            } else {
                $analysis_html .= ('<td></td>'x2);
            }
            $analysis_html.='</tr>'.$/;
            if (defined($post_graph_text)) {
                $analysis_html.= '<tr><td colspan="4" align="center">'.
                    $post_graph_text.'</td></tr>'.$/;
            }
        } elsif ($no_data_text ne '') {
            $analysis_html.='<tr><td colspan="4" align="center">'.
                &mt($no_data_text,
                    $plot_num,$foil_choice_data->{'_count'},
                    $correct,                    
                    $foil_choice_data->{'_count'}-$correct,
                    @extra_data);
            if (defined($post_graph_text)) {
                $analysis_html.='<br />'.$post_graph_text;
            }
            $analysis_html.='</td></tr>'.$/;
        }
    } # end of loop for plots
    $analysis_html.='</table>';
    $r->print($analysis_html);
}

sub ensure_start_end_times {
    my ($start,$end,$first,$last,$plot_num) = @_;
    if (! defined($start) || ! defined($end)) {
        my $sec_in_day = 86400;
        my ($sday,$smon,$syear) = 
            (localtime($last - $sec_in_day*($plot_num-1)))[3..5];
        $start = &Time::Local::timelocal(0,0,0,$sday,$smon,$syear);
        $end   = $start + $sec_in_day;
        if ($plot_num == $ENV{'form.NumPlots'}) {
            $start = $first;
        }
    }
    return ($start,$end);
}

sub RR_concept_plot {
    my ($concepts,$foil_data,$title) = @_;
    #
    my %correct_by_concept;
    my %incorrect_by_concept;
    my %true;
    foreach my $concept (@$concepts) {
        foreach my $foil (@{$concept->{'foils'}}) {
            next if (! exists($foil_data->{$foil}));
            foreach my $choice (keys(%{$foil_data->{$foil}})) {
                if ($choice eq $foil) {
                    $correct_by_concept{$concept->{'name'}} +=
                        $foil_data->{$foil}->{$choice};
                } else {
                    $incorrect_by_concept{$concept->{'name'}} +=
                        $foil_data->{$foil}->{$choice};
                    
                }
            }
        }
    }
    # 
    # need arrays for incorrect and correct because we want to use different
    # colors for them
    my @correct;
    #
    my $total =0;
    for (my $i=0;$i<scalar(@$concepts);$i++) {
        my $concept = $concepts->[$i];
        $correct[$i]   =   $correct_by_concept{$concept->{'name'}};
        $total += $correct_by_concept{$concept->{'name'}}+
            $incorrect_by_concept{$concept->{'name'}};
    }
    if ($total == 0) { return ''; };
    for (my $i=0;$i<=$#correct;$i++) { 
        $correct[$i] = sprintf('%0f',$correct[$i]/$total*100);
    }
    my $xlabel = 'concept';
    my $plot=  &Apache::loncommon::DrawBarGraph($title,
                                                $xlabel,
                                                'Percent Choosing',
                                                100,
                                                ['#33ff00','#ff3300'],
                                                undef,
                                                \@correct);
    return $plot;
}

sub RR_create_percent_selected_plot {
    my ($concepts,$foils,$foil_data,$title) = @_;
    #
    if ($foil_data->{'_count'} == 0) { return ''; };
    my %correct_selections;
    my %incorrect_selections;
    foreach my $foil (@$foils) {
        # foil_data has format $foil_data->{true_foil}->{selected foil}=count
        next if (! exists($foil_data->{$foil}));
        while (my ($f,$count)= each(%{$foil_data->{$foil}})) {
            if ($f eq $foil) {
                $correct_selections{$foil} += $count;
            } else {
                $incorrect_selections{$f} += $count;
            }
        }
    }
    # 
    # need arrays for incorrect and correct because we want to use different
    # colors for them
    my @correct;
    my @incorrect;
    #
    my $total = $foil_data->{'_count'};
    for (my $i=0;$i<scalar(@$foils);$i++) {
        my $foil = $foils->[$i];
        $correct[$i]   = $correct_selections{$foil};
        $incorrect[$i] = $incorrect_selections{$foil};
    }
    for (my $i=0;$i<=$#correct;$i++) { 
        $correct[$i] = sprintf('%2f',$correct[$i]/$total*100);
    }
    for (my $i=0;$i<=$#incorrect;$i++) {
        $incorrect[$i] = sprintf('%2f',$incorrect[$i]/$total*100);
    }
    #
    # Put a blank in the data sets between concepts, if there are concepts
    my @labels;
    if (defined($concepts) && scalar(@$concepts) > 1) {
        my @new_correct;
        my @new_incorrect;
        my $foil_count = 0;
        foreach my $concept (@$concepts) {
            foreach (@{$concept->{'foils'}}) {
                push(@new_correct,  $correct[$foil_count]);
                push(@new_incorrect,$incorrect[$foil_count]);
                push(@labels,++$foil_count);
            }
            push(@new_correct,'');
            push(@new_incorrect,'');
            push(@labels,'');
        }
        @correct = @new_correct;
        @incorrect = @new_incorrect;
    } else {
        @labels = (1 .. scalar(@correct));
    }
    #
    my $xlabel = 'foil chosen';
    my $plot=  &Apache::loncommon::DrawBarGraph($title,
                                                $xlabel,
                                                'Percent Choosing',
                                                100,
                                                ['#33ff00','#ff3300'],
                                                \@labels,
                                                \@correct,
                                                \@incorrect);
    return $plot;
}

sub RR_create_stacked_selection_plot {
    my ($foils,$foil_data,$title,$true_foils)=@_;
    #
    my @dataset; # array of array refs - multicolor rows $datasets[row]->[col]
    my @labels;
    my $count;
    my %column; # maps foil name to column in @datasets
    for (my $i=0;$i<scalar(@$foils);$i++) {
        my $foil = $foils->[$i];
        if (defined($true_foils) && scalar(keys(%$true_foils)) > 0 ) {
            next if (! $true_foils->{$foil} );
            push(@labels,$i+1);
        } else {
            next if (! exists($foil_data->{$foil}));
            push(@labels,$i+1);
        }
        next if (! exists($foil_data->{$foils->[$i]}));
        $column{$foil}= $count++;
        for (my $j=0;$j<scalar(@$foils);$j++) {
            my $value = 0;
            if ($i != $j ) {
                $value += $foil_data->{$foil}->{$foils->[$j]};
            }
            $dataset[$j]->[$column{$foil}]=$value;
        }
    }
    #
    return '' if (! scalar(keys(%column)));
    #
    my $grand_total = 0;
    my %count_per_foil;
    while (my ($foil,$bar) = each (%column)) {
        my $bar_total = 0;
        for (my $j=0;$j<scalar(@dataset);$j++) {
            $bar_total += $dataset[$j]->[$bar];
        }
        next if ($bar_total == 0);
        for (my $j=0;$j<scalar(@dataset);$j++) {
            $dataset[$j]->[$bar] = 
                sprintf('%2f',$dataset[$j]->[$bar]/$bar_total * 100);
        }
        $count_per_foil{$foil}=' ( '.$bar_total.' )';
        $grand_total += $bar_total;
    }
    if ($grand_total == 0) {
        return ('',undef);
    }
    my @empty_row = ();
    foreach (@{$dataset[0]}) {
        push(@empty_row,0);
    }
    #
    my $graph = &Apache::loncommon::DrawBarGraph
        ($title,'Correct Foil','foils chosen Incorrectly',
         100,$plotcolors,\@labels,\@empty_row,@dataset);
    return ($graph,\%count_per_foil);
}


#########################################################
#########################################################
##
##       Misc routines
##
#########################################################
#########################################################

# if $correct is a hash ref, it is assumed to be indexed by student names.
#    the values are assumed to be hash refs with a key of 'answer'.
sub classify_response_data {
    my ($full_row_data,$correct,$function) = @_;
    my %submission_data;
    my %students;
    my $max=0;
    foreach my $row (@$full_row_data) {
        my %subm = &hashify_attempt($row);
        if (ref($correct) eq 'HASH') {
            $subm{'correct'} = $correct->{$subm{'student'}};
        } else {
            $subm{'correct'} = $correct;
        }
        $subm{'submission'} =~ s/=\d+\s*$//;
        if (&$function(\%subm)) {
            $students{$subm{'student'}}++;
            $submission_data{'_count'}++;
            if (&submission_is_correct($subm{'award'})) { 
                $submission_data{'_correct'}++;
            }
            
            if($max<++$submission_data{$subm{'correct'}}->{$subm{'submission'}}) {
                $max=$submission_data{$subm{'correct'}}->{$subm{'submission'}};
            }
        }
    }
    $submission_data{'_max'} = $max;
    $submission_data{'_students'}=scalar(keys(%students));
    return \%submission_data;
}


#########################################################
#########################################################
##
##      Option Response Routines
##
#########################################################
#########################################################
sub OptionResponseAnalysis {
    my ($r,$problem,$problem_data,$Students) = @_;
    my ($resource,$respid) = ($problem->{'resource'},
                              $problem->{'respid'});
    # Note: part data is not needed.
    my $PerformanceData = &Apache::loncoursedata::get_response_data
        (\@Apache::lonstatistics::SelectedSections,
         $Apache::lonstatistics::enrollment_status,
         $resource->{'symb'},$respid);
    if (! defined($PerformanceData) || 
        ref($PerformanceData) ne 'ARRAY' ) {
        $r->print('<h2>'.
                  &mt('There is no student data for this problem.').
                  '</h2>');
    }  else {
        $r->rflush();
        if (exists($ENV{'form.ExcelOutput'})) {
            my $result = &OR_excel_sheet($r,$resource,
                                         $PerformanceData,
                                         $problem_data);
            $r->print($result);
            $r->rflush();
        } else {
            if ($ENV{'form.AnalyzeOver'} eq 'tries') {
                my $analysis_html = &OR_tries_analysis($r,
                                                    $PerformanceData,
                                                    $problem_data);
                $r->print($analysis_html);
                $r->rflush();
            } elsif ($ENV{'form.AnalyzeOver'} eq 'time') {
                my $analysis_html = &OR_time_analysis($PerformanceData,
                                                   $problem_data);
                $r->print($analysis_html);
                $r->rflush();
            } else {
                $r->print('<h2>'.
                          &mt('The analysis you have selected is '.
                              'not supported at this time').
                          '</h2>');
            }
        }
    }
}

#########################################################
#
#       Option Response:  tries Analysis
#
#########################################################
sub OR_tries_analysis {
    my ($r,$PerformanceData,$ORdata) = @_;
    my $mintries = 1;
    my $maxtries = $ENV{'form.NumPlots'};
    my ($table,$Foils,$Concepts) = &build_foil_index($ORdata);
    if (! defined($Concepts)) {
        $Concepts = [];
    }
    my %response_data = &OR_analyze_by_tries($r,$PerformanceData,
                                                     $mintries,$maxtries);
    my $analysis = '';
    #
    # Compute the data necessary to make the plots
    my @foil_plot; 
    my @concept_data;
    for (my $j=0;$j<=scalar(@$Concepts);$j++) {
        my $concept = $Concepts->[$j];
        foreach my $foilid (@{$concept->{'foils'}}) {
            for (my $try=$mintries;$try<=$maxtries;$try++) {
                # concept analysis data
                $concept_data[$j]->[$try]->{'_correct'} +=
                    $response_data{$foilid}->[$try]->{'_correct'};
                $concept_data[$j]->[$try]->{'_total'} +=
                    $response_data{$foilid}->[$try]->{'_total'};
                #
                # foil analysis data
                if ($response_data{$foilid}->[$try]->{'_total'} == 0) {
                    push(@{$foil_plot[$try]->{'_correct'}},0);
                } else {
                    push(@{$foil_plot[$try]->{'_correct'}},
                         100*$response_data{$foilid}->[$try]->{'_correct'}/
                         $response_data{$foilid}->[$try]->{'_total'});
                }
                foreach my $option (@{$ORdata->{'_Options'}}) {
                    push(@{$foil_plot[$try]->{'_total'}},
                         $response_data{$foilid}->[$try]->{'_total'});
                    if ($response_data{$foilid}->[$try]->{'_total'} == 0) {
                        push (@{$foil_plot[$try]->{$option}},0);
                    } else {
                        if ($response_data{$foilid}->[$try]->{'_total'} ==
                            $response_data{$foilid}->[$try]->{'_correct'}) {
                            push(@{$foil_plot[$try]->{$option}},0);
                        } else {
                            push (@{$foil_plot[$try]->{$option}},
                                  100 * 
                                  $response_data{$foilid}->[$try]->{$option} / 
                                  ($response_data{$foilid}->[$try]->{'_total'} 
                                   - 
                                   $response_data{$foilid}->[$try]->{'_correct'}
                                   ));
                        }
                    }
                } # End of foreach my $option
            }
        } # End of foreach my $foilid
    } # End of concept loops
    # 
    # Build a table for the plots
    my $analysis_html = "<br /><table>\n";
    my $optionkey = &build_option_index($ORdata);
    my $num_concepts = 1;
    if (defined($Concepts)) { $num_concepts = scalar(@$Concepts); }
    #
    for (my $try=$mintries;$try<=$maxtries;$try++) {
        if (! defined($response_data{'_total'}->[$try]) ||
            $response_data{'_total'}->[$try] == 0) { 
            if ($try > 1) {
                $analysis_html.= '<tr><td align="center" colspan="4"><b>'.
                    &mt('None of the selected students attempted the problem more than [_1] times.',$try-1).
                    '</b></td></tr>';
            } else {
                $analysis_html.= '<tr><td colspan="4" align="center"><b>'.
                    &mt('None of the selected students have attempted the problem').'</b></td></tr>';
            }
            last;
        }
        my $concept_graph='';
        if ($num_concepts > 1) {
            #
            # Create concept plot
            my @concept_plot_data;
            for (my $j=0;$j<=$#concept_data;$j++) {
                my $total = $concept_data[$j]->[$try]->{'_total'};
                if ($total == 0) {
                    $concept_plot_data[$j] = 0;
                } else {
                    $concept_plot_data[$j] = 100 * 
                        sprintf('%0.3f',
                                $concept_data[$j]->[$try]->{'_correct'} / 
                                $total);
                }
            }
            #
            $concept_graph = &Apache::loncommon::DrawBarGraph
                ('Correct Concepts','Concept Number','Percent Correct',
                 100,$plotcolors,undef,\@concept_plot_data,{xskip=>1});
        }
        #
        # Create Foil Plots
        my $data_count = $response_data{'_total'}->[$try];
        my $correct = $response_data{'_correct'}->[$try];
        my @Datasets;
        foreach my $option ('_correct',@{$ORdata->{'_Options'}}) {
            next if (! exists($foil_plot[$try]->{$option}));
            push(@Datasets,$foil_plot[$try]->{$option});
        }
        #
        # Put a blank in the data set between concepts
        for (my $set =0;$set<=$#Datasets;$set++) {
            my @Data = @{$Datasets[$set]};
            my $idx = 0;
            foreach my $concept (@{$Concepts}) {
                foreach my $foilid (@{$concept->{'foils'}}) {
                    $Datasets[$set]->[$idx++]=shift(@Data);
                }
                if ($concept->{'name'} ne $Concepts->[-1]->{'name'}) {
                    $Datasets[$set]->[$idx++] = 0;
                }
            }
        }
        #
        # Set up the labels needed for the bar graph
        my @Labels;
        my $idx = 1;
        foreach my $concept (@{$Concepts}) {
            foreach my $foilid (@{$concept->{'foils'}}) {
                push(@Labels,$idx++);
            }
            push(@Labels,'');
        }
        #
        my $correct_graph = &Apache::loncommon::DrawBarGraph
            ('Correct Statements','Statement','% Answered Correct',
             100,$plotcolors,\@Labels,$Datasets[0],{xskip=>1});
        
        #
        #
        next if (! defined($Datasets[0]));
        for (my $i=0; $i< scalar(@{$Datasets[0]});$i++) {
            $Datasets[0]->[$i]=0;
        }
        my $count = $response_data{'_total'}->[$try] - 
                                           $response_data{'_correct'}->[$try];
        my $incorrect_graph = &Apache::loncommon::DrawBarGraph
            ('Incorrect Statements','Statement','% Chosen Incorrectly',
             100,$plotcolors,\@Labels,@Datasets,{xskip=>1});
        $analysis_html.= 
            '<tr><td colspan="4" align="center">'.
            '<font size="+1">'.
            &mt('Attempt [_1], [_2] submissions, [_3] correct, [_4] incorrect',
                $try,$data_count,$correct,$data_count-$correct).
            '</font>'.'</td></tr>'.$/.                
            '<tr>'.
            '<td>'.$concept_graph.'</td>'.
            '<td>'.$correct_graph.'</td>'.
            '<td>'.$incorrect_graph.'</td>'.
            '<td>'.$optionkey.'<td>'.
            '</tr>'.$/;
    }
    $analysis_html .= "</table>\n";
    $table .= $analysis_html;
    return $table;
}

sub OR_analyze_by_tries {
    my ($r,$PerformanceData,$mintries,$maxtries) = @_;
    my %Trydata;
    $mintries = 1         if (! defined($mintries) || $mintries < 1);
    $maxtries = $mintries if (! defined($maxtries) || $maxtries < $mintries);
    my @students;
    foreach my $row (@$PerformanceData) {
        next if (! defined($row));
        my $tries = &get_tries_from_row($row);
        my %Row   = &Process_OR_Row($row);
        next if (! %Row);
        my $student_id = $row->[&Apache::loncoursedata::RD_student_id()];
        $students[$tries]->{$student_id}++;
        while (my ($foilid,$href) = each(%Row)) {
            if (! ref($href)) { 
                $Trydata{$foilid}->[$tries] += $href;
                next;
            }
            while (my ($option,$value) = each(%$href)) {
                $Trydata{$foilid}->[$tries]->{$option}+=$value;
            }
        }
    }
    for (my $try=$mintries;$try<=$maxtries;$try++) {
        $Trydata{'_studentcount'}->[$try] = scalar(keys(%{$students[$try]}));
    }
    return %Trydata;
}

#########################################################
#
#     Option Response: Time Analysis
#
#########################################################
sub OR_time_analysis {
    my ($performance_data,$ORdata) = @_;
    my ($table,$Foils,$Concepts) = &build_foil_index($ORdata);
    my $foilkey = &build_option_index($ORdata);
    my $num_concepts = 1;
    if (defined($Concepts)) { $num_concepts = scalar(@$Concepts); }
    #
    if ($num_concepts < 2) {
        $table = '<h3>'.
            &mt('Not enough data for concept analysis.  '.
                'Performing Foil Analysis').
                '</h3>'.$table;
    }
    #
    my $num_plots = $ENV{'form.NumPlots'};
    my $num_data = scalar(@$performance_data)-1;
    #
    my $current_index;
    $table .= "<table>\n";
    for (my $i=0;$i<$num_plots;$i++) {
        ##
        my $starttime = &Apache::lonhtmlcommon::get_date_from_form
            ('startdate_'.$i);
        my $endtime = &Apache::lonhtmlcommon::get_date_from_form
            ('enddate_'.$i);
        if (! defined($starttime) || ! defined($endtime)) {
            my $sec_in_day = 86400;
            my $last_sub_time = &get_time_from_row($performance_data->[-1]);
            my ($sday,$smon,$syear) = 
                (localtime($last_sub_time - $sec_in_day*$i))[3..5];
            $starttime = &Time::Local::timelocal(0,0,0,$sday,$smon,$syear);
            $endtime = $starttime + $sec_in_day;
            if ($i == ($num_plots -1 )) {
                $starttime = &get_time_from_row($performance_data->[0]);
            }
        }
        $table .= '<tr><td colspan="4" align="center"><font size="+1">'.
            &mt('Data from [_1] to [_2]',
                &Apache::lonlocal::locallocaltime($starttime),
                &Apache::lonlocal::locallocaltime($endtime)).
                '</font></td></tr>'.$/;
        my $startdateform = &Apache::lonhtmlcommon::date_setter
            ('Statistics','startdate_'.$i,$starttime);
        my $enddateform = &Apache::lonhtmlcommon::date_setter
            ('Statistics','enddate_'.$i,$endtime);
        #
        my $begin_index;
        my $end_index;
        my $j;
        while (++$j < scalar(@$performance_data)) {
            last if (&get_time_from_row($performance_data->[$j]) 
                                                              > $starttime);
        }
        $begin_index = $j;
        while ($j < scalar(@$performance_data)) {
            if (&get_time_from_row($performance_data->[$j]) > $endtime) {
                last;
            } else {
                $j++;
            }
        }
        $end_index = $j;
        ##
        my ($processed_time_data,$correct,$data_count,$student_count) =
            &OR_time_process_data($performance_data,$begin_index,$end_index);
        ##
        $table .= '<tr><td colspan="4" align="center"><font size="+1">'.
            &mt('[_1] submissions from [_2] students, [_3] correct, [_4] incorrect',
                $data_count,$student_count,$correct,$data_count-$correct).
                '</font></td></tr>'.$/;
        my $concept_correct_plot = '';
        if ($num_concepts > 1) {
            $concept_correct_plot = 
                &OR_Concept_Time_Analysis($processed_time_data,
                                          $correct,$data_count,$student_count,
                                          $ORdata,$Concepts);
        }
        my ($foil_correct_plot,$foil_incorrect_plot) = 
            &OR_Foil_Time_Analysis($processed_time_data,
                                   $correct,$data_count,$student_count,
                                   $ORdata,$Foils,$Concepts);
        $table .= '<tr>'.
            '<td>'.$concept_correct_plot.'</td>'.
            '<td>'.$foil_correct_plot.'</td>'.
            '<td>'.$foil_incorrect_plot.'</td>'.
            '<td align="left" valign="top">'.$foilkey.'</td></tr>'.$/;
        $table .= '<tr><td colspan="4" align="center">'.
            &mt('Start time: [_1]',$startdateform).'<br />'.
            &mt('End time: [_1]',$enddateform).'</td></tr>'.$/;
        $table.= '<tr><td colspan="4">&nbsp</td></tr>'.$/;
    }
    $table .= '</table>';
    #
    return $table;
}

sub OR_Foil_Time_Analysis {
    my ($processed_time_data,$correct,$data_count,$student_count,
        $ORdata,$Foils,$Concepts) = @_;
    if ($data_count <= 0) {
        return ('<h2>'.&mt('There is no data to plot').'</h2>','');
    }
    my $analysis_html;
    my @plotdata;
    my @labels;
    foreach my $concept (@{$Concepts}) {
        foreach my $foil (@{$concept->{'foils'}}) {
            push(@labels,scalar(@labels)+1);
            my $total = $processed_time_data->{$foil}->{'_total'};
            if ($total == 0) {
                push(@{$plotdata[0]},0);
            } else {
                push(@{$plotdata[0]},
                     100 * $processed_time_data->{$foil}->{'_correct'} / $total);
            }
            my $total_incorrect = $total - $processed_time_data->{$foil}->{'_correct'};
            for (my $i=0;$i<scalar(@{$ORdata->{'_Options'}});$i++) {
                my $option = $ORdata->{'_Options'}->[$i];
                if ($total_incorrect == 0) {
                    push(@{$plotdata[$i+1]},0);
                } else {
                    push(@{$plotdata[$i+1]},
                         100 * $processed_time_data->{$foil}->{$option} / $total_incorrect);
                }
            }
        }
        # Put in a blank one
        push(@labels,'');
        push(@{$plotdata[0]},0);
        for (my $i=0;$i<scalar(@{$ORdata->{'_Options'}});$i++) {
            push(@{$plotdata[$i+1]},0);
        }
    }
    #
    # Create the plot
    my $correct_plot = &Apache::loncommon::DrawBarGraph('Correct Statements',
                                                        'Statement Number',
                                                        'Percent Correct',
                                                        100,
                                                        $plotcolors,
                                                        undef,
                                                        $plotdata[0],
                                                        {xskip=>1});
    for (my $j=0; $j< scalar(@{$plotdata[0]});$j++) {
        $plotdata[0]->[$j]=0;
    }
    my $incorrect_plot = 
        &Apache::loncommon::DrawBarGraph('Incorrect Statements',
                                         'Statement Number',
                                         'Incorrect Option Choice',
                                         100,
                                         $plotcolors,
                                         undef,
                                         @plotdata,{xskip=>1});
    return ($correct_plot,$incorrect_plot);
}

sub OR_Concept_Time_Analysis {
    my ($processed_time_data,$correct,$data_count,$student_count,
        $ORdata,$Concepts) = @_;
    return '' if ($data_count == 0);
    #
    # Put the data in plottable form
    my @plotdata;
    foreach my $concept (@$Concepts) {
        my ($total,$correct);
        foreach my $foil (@{$concept->{'foils'}}) {
            $total += $processed_time_data->{$foil}->{'_total'};
            $correct += $processed_time_data->{$foil}->{'_correct'};
        }
        if ($total == 0) {
            push(@plotdata,0);
        } else {
            push(@plotdata,100 * $correct / $total);
        }
    }
    #
    # Create the plot
    return &Apache::loncommon::DrawBarGraph('Correct Concepts',
                                            'Concept Number',
                                            'Percent Correct',
                                            100,
                                            $plotcolors,
                                            undef,
                                            \@plotdata,{xskip=>1});
}

sub OR_time_process_data {
    my ($performance_data,$begin_index,$end_index)=@_;
    my %processed_time_data;
    my %distinct_students;
    my ($correct,$data_count);
    if (($begin_index == $end_index) && 
        ($end_index != scalar(@$performance_data)-1)) { 
        return undef;
    }
    # Be sure we include the last one if we are asked for it.
    # That we have to correct here (and not when $end_index is 
    # given a value) should probably be considered a bug.
    if ($end_index == scalar(@$performance_data)-1) {
        $end_index++;
    }
    my $count;
    for (my $i=$begin_index;$i<$end_index;$i++) {
        my $attempt = $performance_data->[$i];
        $count++;
        next if (! defined($attempt));
        my %attempt = &Process_OR_Row($attempt);
        $data_count++;
        $correct += $attempt{'_correct'};
        $distinct_students{$attempt->[&Apache::loncoursedata::RD_student_id()]}++;
        while (my ($foilid,$href) = each(%attempt)) {
            if (! ref($href)) {
                $processed_time_data{$foilid} += $href;
                next;
            }
            while (my ($option,$value) = each(%$href)) {
                $processed_time_data{$foilid}->{$option}+=$value;
            }
        }
    }
    return (\%processed_time_data,$correct,$data_count,
            scalar(keys(%distinct_students)));
}

#########################################################
#########################################################
##
##             Excel output 
##
#########################################################
#########################################################
sub build_student_data_worksheet {
    my ($workbook,$format) = @_;
    my $rows_output = 3;
    my $cols_output = 0;
    my $worksheet  = $workbook->addworksheet('Student Data');
    $worksheet->write($rows_output++,0,'Student Data',$format->{'h3'});
    my @Headers = ('full name','username','domain','section',
                   "student\nnumber",'identifier');
    $worksheet->write_row($rows_output++,0,\@Headers,$format->{'header'});
    my @Students = @Apache::lonstatistics::Students;
    my $studentrows = &Apache::loncoursedata::get_student_data(\@Students);
    my %ids;
    foreach my $row (@$studentrows) {
        my ($mysqlid,$student) = @$row;
        $ids{$student}=$mysqlid;
    }
    foreach my $student (@Students) {
        my $name_domain = $student->{'username'}.':'.$student->{'domain'};
        $worksheet->write_row($rows_output++,0,
                          [$student->{'fullname'},
                           $student->{'username'},$student->{'domain'},
                           $student->{'section'},$student->{'id'},
                           $ids{$name_domain}]);
    }
    return $worksheet;
}

sub OR_excel_sheet {
    my ($r,$resource,$performance_data,$ORdata) = @_;
    my $response = '';
    my (undef,$Foils,$Concepts) = &build_foil_index($ORdata);
    #
    # Create excel worksheet
    my $filename = '/prtspool/'.
        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
        time.'_'.rand(1000000000).'.xls';
    my $workbook  = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
    if (! defined($workbook)) {
        $r->log_error("Error creating excel spreadsheet $filename: $!");
        $r->print('<p>'.&mt("Unable to create new Excel file.  ".
                            "This error has been logged.  ".
                            "Please alert your LON-CAPA administrator").
                  '</p>');
        return undef;
    }
    #
    $workbook->set_tempdir('/home/httpd/perl/tmp');
    my $format = &Apache::loncommon::define_excel_formats($workbook);
    #
    # Create and populate main worksheets
    my $problem_data_sheet  = $workbook->addworksheet('Problem Data');
    my $student_data_sheet = &build_student_data_worksheet($workbook,$format);
    my $response_data_sheet = $workbook->addworksheet('Response Data');
    foreach my $sheet ($problem_data_sheet,$student_data_sheet,
                       $response_data_sheet) {
        $sheet->write(0,0,$resource->{'title'},$format->{'h2'});
        $sheet->write(1,0,$resource->{'src'},$format->{'h3'});
    }
    #
    my $result;
    $result = &OR_build_problem_data_worksheet($problem_data_sheet,$format,
                                            $Concepts,$ORdata);
    if ($result ne 'okay') {
        # Do something useful
    }
    $result = &OR_build_response_data_worksheet($response_data_sheet,$format,
                                             $performance_data,$Foils,
                                             $ORdata);
    if ($result ne 'okay') {
        # Do something useful
    }
    $response_data_sheet->activate();
    #
    # Close the excel file
    $workbook->close();
    #
    # Write a link to allow them to download it
    $result .= '<h2>'.&mt('Excel Raw Data Output').'</h2>'.
              '<p><a href="'.$filename.'">'.
              &mt('Your Excel spreadsheet.').
              '</a></p>'."\n";
    return $result;
}

sub OR_build_problem_data_worksheet {
    my ($worksheet,$format,$Concepts,$ORdata) = @_;
    my $rows_output = 3;
    my $cols_output = 0;
    $worksheet->write($rows_output++,0,'Problem Structure',$format->{'h3'});
    ##
    ##
    my @Headers;
    if (@$Concepts > 1) {
        @Headers = ("Concept\nNumber",'Concept',"Foil\nNumber",
                    'Foil Name','Foil Text','Correct value');
    } else {
        @Headers = ('Foil Number','FoilName','Foil Text','Correct value');
    }
    $worksheet->write_row($rows_output++,0,\@Headers,$format->{'header'});
    my %Foildata = %{$ORdata->{'_Foils'}};
    my $conceptindex = 1;
    my $foilindex = 1;
    foreach my $concept (@$Concepts) {
        my @FoilsInConcept = @{$concept->{'foils'}};
        my $firstfoil = shift(@FoilsInConcept);
        if (@$Concepts > 1) {
            $worksheet->write_row($rows_output++,0,
                                  [$conceptindex,
                                   $concept->{'name'},
                                   $foilindex++,
                                   $Foildata{$firstfoil}->{'name'},
                                   $Foildata{$firstfoil}->{'text'},
                                   $Foildata{$firstfoil}->{'value'},]);
        } else {
            $worksheet->write_row($rows_output++,0,
                                  [ $foilindex++,
                                    $Foildata{$firstfoil}->{'name'},
                                    $Foildata{$firstfoil}->{'text'},
                                    $Foildata{$firstfoil}->{'value'},]);
        }
        foreach my $foilid (@FoilsInConcept) {
            if (@$Concepts > 1) {
                $worksheet->write_row($rows_output++,0,
                                      ['',
                                       '',
                                       $foilindex,
                                       $Foildata{$foilid}->{'name'},
                                       $Foildata{$foilid}->{'text'},
                                       $Foildata{$foilid}->{'value'},]);
            } else {
                $worksheet->write_row($rows_output++,0,                
                                      [$foilindex,
                                       $Foildata{$foilid}->{'name'},
                                       $Foildata{$foilid}->{'text'},
                                       $Foildata{$foilid}->{'value'},]);
            }                
        } continue {
            $foilindex++;
        }
    } continue {
        $conceptindex++;
    }
    $rows_output++;
    $rows_output++;
    ##
    ## Option data output
    $worksheet->write($rows_output++,0,'Options',$format->{'header'});
    foreach my $string (@{$ORdata->{'_Options'}}) {
        $worksheet->write($rows_output++,0,$string);
    }
    return 'okay';
}

sub OR_build_response_data_worksheet {
    my ($worksheet,$format,$performance_data,$Foils,$ORdata)=@_;
    my $rows_output = 3;
    my $cols_output = 0;
    $worksheet->write($rows_output++,0,'Response Data',$format->{'h3'});
    $worksheet->set_column(1,1,20);
    $worksheet->set_column(2,2,13);
    my @Headers = ('identifier','time','award detail','attempt');
    foreach my $foil (@$Foils) {
        push (@Headers,$foil.' submission');
        push (@Headers,$foil.' grading');
    }
    $worksheet->write_row($rows_output++,0,\@Headers,$format->{'header'});
    #
    foreach my $row (@$performance_data) {
        next if (! defined($row));
        my ($student,$award,$grading,$submission,$time,$tries) = @$row;
        my @Foilgrades = split('&',$grading);
        my @Foilsubs   = split('&',$submission);
        my %response_data;
        for (my $j=0;$j<=$#Foilgrades;$j++) {
            my ($foilid,$correct)  = split('=',$Foilgrades[$j]);
            my (undef,$submission) = split('=',$Foilsubs[$j]);
            $submission = &Apache::lonnet::unescape($submission);
            $foilid = &Apache::lonnet::unescape($foilid);
            $response_data{$foilid.' submission'}=$submission;
            $response_data{$foilid.' award'}=$correct;
        }
        $worksheet->write($rows_output,$cols_output++,$student);
        $worksheet->write($rows_output,$cols_output++,
             &Apache::lonstathelpers::calc_serial($time),$format->{'date'});
        $worksheet->write($rows_output,$cols_output++,$award);
        $worksheet->write($rows_output,$cols_output++,$tries);
        foreach my $foilid (@$Foils) {
            $worksheet->write($rows_output,$cols_output++,
                              $response_data{$foilid.' submission'});
            $worksheet->write($rows_output,$cols_output++,
                              $response_data{$foilid.' award'});
        }
        $rows_output++;
        $cols_output = 0;
    }
    return;
}

sub build_foil_index {
    my ($ORdata) = @_;
    return if (! exists($ORdata->{'_Foils'}));
    my %Foildata = %{$ORdata->{'_Foils'}};
    my @Foils = sort(keys(%Foildata));
    my %Concepts;
    foreach my $foilid (@Foils) {
        push(@{$Concepts{$Foildata{$foilid}->{'_Concept'}}},
             $foilid);
    }
    undef(@Foils);
    # Having gathered the concept information in a hash, we now translate it
    # into an array because we need to be consistent about order.
    # Also put the foils in order, too.
    my $sortfunction = sub {
        my %Numbers = (one   => 1,
                       two   => 2,
                       three => 3,
                       four  => 4,
                       five  => 5,
                       six   => 6,
                       seven => 7,
                       eight => 8,
                       nine  => 9,
                       ten   => 10,);
        my $a1 = lc($a); 
        my $b1 = lc($b);
        if (exists($Numbers{$a1})) {
            $a1 = $Numbers{$a1};
        }
        if (exists($Numbers{$b1})) {
            $b1 = $Numbers{$b1};
        }
        if (($a1 =~/^\d+$/) && ($b1 =~/^\d+$/)) {
            return $a1 <=> $b1;
        } else {
            return $a1 cmp $b1;
        }
    };
    my @Concepts;
    foreach my $concept (sort $sortfunction (keys(%Concepts))) {
        if (! defined($Concepts{$concept})) {
            $Concepts{$concept}=[];
#            next;
        }
        push(@Concepts,{ name => $concept,
                        foils => [@{$Concepts{$concept}}]});
        push(@Foils,(@{$Concepts{$concept}}));
    }
    #
    # Build up the table of row labels.
    my $table = '<table border="1" >'."\n";
    if (@Concepts > 1) {
        $table .= '<tr>'.
            '<th>'.&mt('Concept Number').'</th>'.
            '<th>'.&mt('Concept').'</th>'.
            '<th>'.&mt('Foil Number').'</th>'.
            '<th>'.&mt('Foil Name').'</th>'.
            '<th>'.&mt('Foil Text').'</th>'.
            '<th>'.&mt('Correct Value').'</th>'.
            "</tr>\n";
    } else {
        $table .= '<tr>'.
            '<th>'.&mt('Foil Number').'</th>'.
            '<th>'.&mt('Foil Name').'</th>'.
            '<th>'.&mt('Foil Text').'</th>'.
            '<th>'.&mt('Correct Value').'</th>'.
            "</tr>\n";
    }        
    my $conceptindex = 1;
    my $foilindex = 1;
    foreach my $concept (@Concepts) {
        my @FoilsInConcept = @{$concept->{'foils'}};
        my $firstfoil = shift(@FoilsInConcept);
        if (@Concepts > 1) {
            $table .= '<tr>'.
                '<td>'.$conceptindex.'</td>'.
                '<td>'.&HTML::Entities::encode($concept->{'name'},'<>&"').'</td>'.
                '<td>'.$foilindex++.'</td>'.
                '<td>'.&HTML::Entities::encode($Foildata{$firstfoil}->{'name'},'<>&"').'</td>'.
                '<td>'.$Foildata{$firstfoil}->{'text'}.'</td>'.
                '<td>'.&HTML::Entities::encode($Foildata{$firstfoil}->{'value'},'<>&"').'</td>'.
                "</tr>\n";
        } else {
            $table .= '<tr>'.
                '<td>'.$foilindex++.'</td>'.
                '<td>'.&HTML::Entities::encode($Foildata{$firstfoil}->{'name'},'<>&"').'</td>'.
                '<td>'.$Foildata{$firstfoil}->{'text'}.'</td>'.
                '<td>'.&HTML::Entities::encode($Foildata{$firstfoil}->{'value'},'<>&"').'</td>'.
                "</tr>\n";
        }
        foreach my $foilid (@FoilsInConcept) {
            if (@Concepts > 1) {
                $table .= '<tr>'.
                    '<td></td>'.
                    '<td></td>'.
                    '<td>'.$foilindex.'</td>'.
                    '<td>'.&HTML::Entities::encode($Foildata{$foilid}->{'name'},'<>&"').'</td>'.
                    '<td>'.$Foildata{$foilid}->{'text'}.'</td>'.
                    '<td>'.&HTML::Entities::encode($Foildata{$foilid}->{'value'},'<>&"').'</td>'.
                    "</tr>\n";
            } else {
                $table .= '<tr>'.
                    '<td>'.$foilindex.'</td>'.
                    '<td>'.&HTML::Entities::encode($Foildata{$foilid}->{'name'},'<>&"').'</td>'.
                    '<td>'.$Foildata{$foilid}->{'text'}.'</td>'.
                    '<td>'.&HTML::Entities::encode($Foildata{$foilid}->{'value'},'<>&"').'</td>'.
                    "</tr>\n";
            }                
        } continue {
            $foilindex++;
        }
    } continue {
        $conceptindex++;
    }
    $table .= "</table>\n";
    #
    # Build option index with color stuff
    return ($table,\@Foils,\@Concepts);
}

sub build_option_index {
    my ($ORdata)= @_;
    my $table = "<table>\n";
    my $optionindex = 0;
    my @Rows;
    foreach my $option (&mt('correct option chosen'),@{$ORdata->{'_Options'}}) {
        my $color = $plotcolors->[$optionindex++];
        push (@Rows,
              '<tr>'.
              '<td bgcolor="'.$color.'">'.
              '<font color="'.$color.'">'.('*'x3).'</font>'.'</td>'.
              '<td>'.&HTML::Entities::encode($option,'<>&"').'</td>'.
              "</tr>\n");
    }
    shift(@Rows); # Throw away 'correct option chosen' color
    $table .= join('',reverse(@Rows));
    $table .= "</table>\n";
}

sub build_foil_key {
    my ($foils,$extra_data)= @_;
    if (! defined($extra_data)) { $extra_data = {}; }
    my $table = "<table>\n";
    my $foil_index = 0;
    my @rows;
    foreach my $foil (&mt('correct foil chosen'),@{$foils}) {
        my $color = $plotcolors->[$foil_index++];
        push (@rows,
              '<tr>'.
              '<td bgcolor="'.$color.'" class="key">'.
              '<font color="'.$color.'">'.('*'x4).'</font></td>'.
              '<td>'.&HTML::Entities::encode($foil,'<>&"').
              ('&nbsp;'x2).$extra_data->{$foil}.'</td>'.
              "</tr>\n");
    }
    shift(@rows); # Throw away 'correct foil chosen' color
    $table .= join('',reverse(@rows));
    $table .= "</table>\n";
}

#########################################################
#########################################################
##
##   Generic Interface Routines
##
#########################################################
#########################################################
sub CreateInterface {
    ##
    ## Environment variable initialization
    if (! exists$ENV{'form.AnalyzeOver'}) {
        $ENV{'form.AnalyzeOver'} = 'tries';
    }
    ##
    ## Build the menu
    my $Str = '';
    $Str .= &Apache::lonhtmlcommon::breadcrumbs
        (undef,'Detailed Problem Analysis');
    $Str .= '<table cellspacing="5">'."\n";
    $Str .= '<tr>';
    $Str .= '<td align="center"><b>'.&mt('Sections').'</b></td>';
    $Str .= '<td align="center"><b>'.&mt('Enrollment Status').'</b></td>';
#    $Str .= '<td align="center"><b>'.&mt('Sequences and Folders').'</b></td>';
    $Str .= '<td align="center">&nbsp;</td>';
    $Str .= '</tr>'."\n";
    ##
    ## 
    $Str .= '<tr><td align="center">'."\n";
    $Str .= &Apache::lonstatistics::SectionSelect('Section','multiple',5);
    $Str .= '</td>';
    #
    $Str .= '<td align="center">';
    $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
    $Str .= '</td>';
    #
#    $Str .= '<td align="center">';
    my $only_seq_with_assessments = sub { 
        my $s=shift;
        if ($s->{'num_assess'} < 1) { 
            return 0;
        } else { 
            return 1;
        }
    };
    &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
                                              $only_seq_with_assessments);
    ##
    ##
    $Str .= '<td>';
    ##
    my $showprob_checkbox = 
        '<input type="checkbox" name="show_prob" value="true" ';
    if ($ENV{'form.show_prob'} eq 'true') {
        $showprob_checkbox .= 'checked ';
    }
    $showprob_checkbox.= ' />';
    $Str.= '<nobr><label>'.
        &mt('Show problem [_1]',$showprob_checkbox).
        '</label></nobr><br />';
    ##
    my $analyze_selector = '<select name="AnalyzeOver" >';
    $analyze_selector .= '<option value="tries" ';
    if (! exists($ENV{'form.AnalyzeOver'}) || 
        $ENV{'form.AnalyzeOver'} eq 'tries'){
        # Default to tries
        $analyze_selector .= ' selected ';
    }
    $analyze_selector .= '>'.&mt('Tries').'</option>';
    $analyze_selector .= '<option value="time" ';
    $analyze_selector .= ' selected ' if ($ENV{'form.AnalyzeOver'} eq 'time');
    $analyze_selector .= '>'.&mt('Time').'</option>';
    $analyze_selector .= '</select>';
    $Str .= '<nobr><label>'.
        &mt('Analyze Over [_1] [_2]',
            $analyze_selector,
            &Apache::loncommon::help_open_topic('Analysis_Analyze_Over')).
            '</label></nobr><br />'.$/;
    ##
    my $numplots_selector = '<select name="NumPlots">';
    if (! exists($ENV{'form.NumPlots'}) 
        || $ENV{'form.NumPlots'} < 1 
        || $ENV{'form.NumPlots'} > 20) {
        $ENV{'form.NumPlots'} = 5;
    }
    foreach my $i (1,2,3,4,5,6,7,8,10,15,20) {
        $numplots_selector .= '<option value="'.$i.'" ';
        if ($ENV{'form.NumPlots'} == $i) { $numplots_selector.=' selected '; }
        $numplots_selector .= '>'.$i.'</option>';
    }
    $numplots_selector .= '</select></nobr><br />';
    $Str .= '<nobr><label>'.&mt('Number of Plots [_1]',$numplots_selector).
        '</label></nobr>';
    ##
    $Str .= '<nobr><label>'.&mt('Status: [_1]',
                                 '<input type="text" '.
                                 'name="stats_status" size="60" value="" />'
                                 ).
                    '</label></nobr>';
    $Str .= '</td>';
    ##
    ##
    $Str .= '</tr>'."\n";
    $Str .= '</table>'."\n";
    return $Str;
}

#########################################################
#########################################################
##
##              Misc Option Response functions
##
#########################################################
#########################################################
sub get_time_from_row {
    my ($row) = @_;
    if (ref($row)) {
        return $row->[&Apache::loncoursedata::RD_timestamp()];
    } 
    return undef;
}

sub get_tries_from_row {
    my ($row) = @_;
    if (ref($row)) {
        return $row->[&Apache::loncoursedata::RD_tries()];
    }
    return undef;
}

sub hashify_attempt {
    my ($row) = @_;
    my %attempt;
    $attempt{'student'}    = $row->[&Apache::loncoursedata::RD_sname()];
    $attempt{'tries'}      = $row->[&Apache::loncoursedata::RD_tries()];
    $attempt{'submission'} = &Apache::lonnet::unescape($row->[&Apache::loncoursedata::RD_submission()]);
    $attempt{'award'}      = $row->[&Apache::loncoursedata::RD_awarddetail()];
    $attempt{'timestamp'}  = $row->[&Apache::loncoursedata::RD_timestamp()];
    return %attempt;
}

sub Process_OR_Row {
    my ($row) = @_;
    my %RowData;
#    my $student_id = $row->[&Apache::loncoursedata::RD_student_id()];
    my $award      = $row->[&Apache::loncoursedata::RD_awarddetail()];
    my $grading    = $row->[&Apache::loncoursedata::RD_response_eval()];
    my $submission = $row->[&Apache::loncoursedata::RD_submission()];
    my $time       = $row->[&Apache::loncoursedata::RD_timestamp()];
#    my $tries      = $row->[&Apache::loncoursedata::RD_tries()];
    return undef if ($award eq 'MISSING_ANSWER');
    if (&submission_is_correct($award)) {
        $RowData{'_correct'} = 1;
    }
    $RowData{'_total'} = 1;
    my @Foilgrades = split('&',$grading);
    my @Foilsubs   = split('&',$submission);
    for (my $j=0;$j<=$#Foilgrades;$j++) {
        my ($foilid,$correct)  = split('=',$Foilgrades[$j]);
        $foilid = &Apache::lonnet::unescape($foilid);
        my (undef,$submission) = split('=',$Foilsubs[$j]);
        if ($correct) {
            $RowData{$foilid}->{'_correct'}++;
        } else {
            $submission = &Apache::lonnet::unescape($submission);
            $RowData{$foilid}->{$submission}++;
        }
        $RowData{$foilid}->{'_total'}++;
    }
    return %RowData;
}

sub submission_is_correct {
    my ($award) = @_;
    if ($award =~ /(APPROX_ANS|EXACT_ANS)/) {
        return 1;
    } else {
        return 0;
    }
}

1;

__END__