--- loncom/interface/statistics/lonproblemstatistics.pm	2004/03/29 15:58:33	1.74
+++ loncom/interface/statistics/lonproblemstatistics.pm	2004/04/01 20:02:56	1.79
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: lonproblemstatistics.pm,v 1.74 2004/03/29 15:58:33 matthew Exp $
+# $Id: lonproblemstatistics.pm,v 1.79 2004/04/01 20:02:56 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -61,6 +61,7 @@ use Apache::lonstathelpers();
 use Time::HiRes;
 
 my @StatsArray;
+my %SeqStat;    # keys are symbs, values are hash refs
 
 ##
 ## Localization notes:
@@ -69,27 +70,63 @@ my @StatsArray;
 ## header for plots created with Graph.pm, both of which more than likely do
 ## not support localization.
 ##
+#
+#
+##
+## Description of Field attributes
+##
+## Attribute     Required   Value       Meaning or Use
+##
+## name            yes      any scalar  Used to uniquely identify field
+## title           yes      any scalar  This is what the user sees to identify
+##                                      the field.  Passed through &mt().
+## long_title      yes      any scalar  Used as graph heading and in excel
+##                                      output.  NOT translated
+## align           no    (left|right|center)  HTML cell contents alignment
+## color           yes      html color  HTML cell background color
+##                                      used to visually group statistics
+## special         no          (link)   Indicates a link, target is name.link
+##                                      Currently set in &get_statistics()
+## graphable       no      (yes|no)     Can a bar graph of the field be 
+##                                      produced?
+## sortable        no      (yes|no)     Should a sort link be put in the
+##                                      column header?
+## selectable      yes     (yes|no)     Can the column be removed from the
+##                                      statistics display?
+## selected        yes     (yes|no)     Is the column selected by default?
+##
 my @Fields = (
            { name => 'problem_num',
              title => 'P#',
              align => 'right',
-             color => '#FFFFE6' },
+             color => '#FFFFE6',
+             selectable => 'no',
+             selected => 'yes',
+           },
            { name   => 'container',
              title  => 'Sequence or Folder',
              align  => 'left',
              color  => '#FFFFE6',
-             sortable => 'yes' },
+             sortable => 'yes',
+             selectable => 'no',
+             selected => 'yes',
+           },
            { name   => 'title',
              title  => 'Title',
              align  => 'left',
              color  => '#FFFFE6',
              special  => 'link',
-             sortable => 'yes', },
+             sortable => 'yes', 
+             selectable => 'no',
+             selected => 'yes',
+           },
            { name   => 'part', 
              title  => 'Part',
              align  => 'left',
              color  => '#FFFFE6',
-             },
+             selectable => 'no',
+             selected => 'yes',
+           },
            { name   => 'num_students',
              title  => '#Stdnts',
              align  => 'right',
@@ -97,7 +134,10 @@ my @Fields = (
              format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Number of Students Attempting Problem' },
+             long_title => 'Number of Students Attempting Problem',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'tries',
              title  => 'Tries',
              align  => 'right',
@@ -105,7 +145,10 @@ my @Fields = (
              format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Total Number of Tries' },
+             long_title => 'Total Number of Tries',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'max_tries',
              title  => 'Max Tries',
              align  => 'right',
@@ -113,7 +156,10 @@ my @Fields = (
              format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Maximum Number of Tries' },
+             long_title => 'Maximum Number of Tries',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'min_tries',
              title  => 'Min Tries',
              align  => 'right',
@@ -121,7 +167,10 @@ my @Fields = (
              format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Minumum Number of Tries' },
+             long_title => 'Minumum Number of Tries',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'mean_tries',
              title  => 'Mean Tries',
              align  => 'right',
@@ -129,7 +178,10 @@ my @Fields = (
              format => '%5.2f',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Average Number of Tries' },
+             long_title => 'Average Number of Tries',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'std_tries',
              title  => 'S.D. tries',
              align  => 'right',
@@ -137,7 +189,10 @@ my @Fields = (
              format => '%5.2f',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Standard Deviation of Number of Tries' },
+             long_title => 'Standard Deviation of Number of Tries',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'skew_tries',
              title  => 'Skew Tries',
              align  => 'right',
@@ -145,7 +200,10 @@ my @Fields = (
              format => '%5.2f',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Skew of Number of Tries' },
+             long_title => 'Skew of Number of Tries',
+             selectable => 'yes',
+             selected => 'no',
+           },
            { name   => 'num_solved',
              title  => '#YES',
              align  => 'right',
@@ -153,7 +211,10 @@ my @Fields = (
              format => '%4.1f',#             format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Number of Students able to Solve' },
+             long_title => 'Number of Students able to Solve',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'num_override',
              title  => '#yes',
              align  => 'right',
@@ -161,7 +222,10 @@ my @Fields = (
              format => '%4.1f',#             format => '%d',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Number of Students given Override' },
+             long_title => 'Number of Students given Override',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'num_wrong',
              title  => '#Wrng',
              align  => 'right',
@@ -169,7 +233,10 @@ my @Fields = (
              format => '%4.1f',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Percent of students whose final answer is wrong' },
+             long_title => 'Percent of students whose final answer is wrong',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'deg_of_diff',
              title  => 'DoDiff',
              align  => 'right',
@@ -178,7 +245,10 @@ my @Fields = (
              sortable  => 'yes',
              graphable => 'yes',
              long_title => 'Degree of Difficulty'.
-                           '[ 1 - ((#YES+#yes) / Tries) ]'},
+                           '[ 1 - ((#YES+#yes) / Tries) ]',
+             selectable => 'yes',
+             selected => 'yes',
+           },
            { name   => 'deg_of_disc',
              title  => 'DoDisc',
              align  => 'right',
@@ -186,9 +256,205 @@ my @Fields = (
              format => '%4.2f',
              sortable  => 'yes',
              graphable => 'yes',
-             long_title => 'Degree of Discrimination' },
+             long_title => 'Degree of Discrimination',
+             selectable => 'yes',
+             selected => 'no',
+           },
+);
+
+my @SeqFields = (
+           { name   => 'title',
+             title  => 'Sequence',
+             align  => 'left',
+             color  => '#FFFFE6',
+             special  => 'no',
+             sortable => 'no', 
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'items',
+             title  => '#Items',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4d',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Number of Items in Sequence',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'scoremean',
+             title  => 'Score Mean',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Mean Sequence Score',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'scorestd',
+             title  => 'Score STD',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Standard Deviation of Sequence Scores',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'scoremax',
+             title  => 'Score Max',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Maximum Sequence Score',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'scoremin',
+             title  => 'Score Min',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Minumum Sequence Score',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'scorecount',
+             title  => 'Score N',
+             align  => 'right',
+             color  => '#FFFFE6',
+             format => '%4d',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Number of Students in score computations',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'countmean',
+             title  => 'Count Mean',
+             align  => 'right',
+             color  => '#FFFFFF',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Mean Sequence Score',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'countstd',
+             title  => 'Count STD',
+             align  => 'right',
+             color  => '#FFFFFF',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Standard Deviation of Sequence Scores',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'countmax',
+             title  => 'Count Max',
+             align  => 'right',
+             color  => '#FFFFFF',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Maximum Number of Correct Problems',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'countmin',
+             title  => 'Count Min',
+             align  => 'right',
+             color  => '#FFFFFF',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Minumum Number of Correct Problems',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'count',
+             title  => 'Count N',
+             align  => 'right',
+             color  => '#FFFFFF',
+             format => '%4d',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'Number of Students in score computations',
+             selectable => 'yes',
+             selected => 'no',
+           },
+           { name   => 'KR-21',
+             title  => 'KR-21',
+             align  => 'right',
+             color  => '#FFAAAA',
+             format => '%4.2f',
+             sortable  => 'no',
+             graphable => 'no',
+             long_title => 'KR-21 reliability statistic',
+             selectable => 'yes',
+             selected => 'no',
+           },           
 );
 
+my %SelectedFields;
+
+sub parse_field_selection {
+    #
+    # Pull out the defaults
+    if (! defined($ENV{'form.fieldselections'})) {
+        $ENV{'form.fieldselections'} = [];
+        foreach my $field (@Fields) {
+            next if ($field->{'selectable'} ne 'yes');
+            if ($field->{'selected'} eq 'yes') {
+                push(@{$ENV{'form.fieldselections'}},$field->{'name'});
+            }
+        }
+    }
+    #
+    # This should not happen, but in case it does...
+    if (ref($ENV{'form.fieldselections'}) ne 'ARRAY') {
+        $ENV{'form.fieldselections'} = [$ENV{'form.fieldselections'}];
+    }
+    #
+    # Set the field data and the selected fields (for easier checking)
+    undef(%SelectedFields);
+    foreach my $field (@Fields) {
+        next if ($field->{'selectable'} ne 'yes');
+        $field->{'selected'} = 'no';
+        foreach my $selection (@{$ENV{'form.fieldselections'}}) {
+            if ($selection eq $field->{'name'} || $selection eq 'all') {
+                $field->{'selected'} = 'yes';
+                $SelectedFields{$field->{'name'}}++;
+            }
+        }
+    }
+    return;
+}
+
+sub field_selection_input {
+    my $Str = '<select name="fieldselections" multiple size="5">'."\n";
+    $Str .= '<option value="all">all</option>'."\n";
+    foreach my $field (@Fields) {
+        next if ($field->{'selectable'} ne 'yes');
+        $Str .= '    <option value="'.$field->{'name'}.'" ';
+        if ($field->{'selected'} eq 'yes') {
+            $Str .= 'selected ';
+        }
+        $Str .= '>'.$field->{'title'}.'</option>'."\n";
+    }
+    $Str .= "</select>\n";
+}
+
 ###############################################
 ###############################################
 
@@ -204,6 +470,7 @@ select sections, maps, and output.
 ###############################################
 ###############################################
 sub CreateInterface {
+    &parse_field_selection();
     my $Str = '';
     $Str .= &Apache::lonhtmlcommon::breadcrumbs
         (undef,'Overall Problem Statistics','Statistics_Overall_Key');
@@ -212,6 +479,7 @@ sub CreateInterface {
     $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"><b>'.&mt('Statistics').'</b></td>';
     $Str .= '<td rowspan="2">'.
         &Apache::lonstathelpers::limit_by_time_form().'</td>';
     $Str .= '</tr>'."\n";
@@ -232,6 +500,7 @@ sub CreateInterface {
     };
     $Str .= &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
                                               $only_seq_with_assessments);
+    $Str .= '</td><td>'.&field_selection_input();
     $Str .= '</td></tr>'."\n";
     $Str .= '</table>'."\n";
     $Str .= '<input type="submit" name="GenerateStatistics" value="'.
@@ -270,7 +539,8 @@ sub BuildProblemStatisticsPage {
                                'statsoutputmode' => 'scalar',
                                'Section' => 'array',
                                'StudentData' => 'array',
-                               'Maps' => 'array');
+                               'Maps' => 'array',
+                               'fieldselections'=> 'array');
     &Apache::loncommon::store_course_settings('statistics',
                                               \%Saveable_Parameters);
     &Apache::loncommon::restore_course_settings('statistics',
@@ -280,6 +550,7 @@ sub BuildProblemStatisticsPage {
     #
     # Clear the package variables
     undef(@StatsArray);
+    undef(%SeqStat);
     #
     # Finally let the user know we are here
     my $interface = &CreateInterface();
@@ -310,26 +581,65 @@ sub BuildProblemStatisticsPage {
     # This probably does not need to be done each time we are called, but
     # it does not slow things down noticably.
     &Apache::loncoursedata::populate_weight_table();
+    #
     if (exists($ENV{'form.Excel'})) {
         &Excel_output($r);
     } else {
+        my $count = 0;
+        foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
+            $count += $seq->{'num_assess_parts'};
+        }
+        if ($count > 10) {
+            $r->print('<h2>'.
+                      &mt('Compiling statistics for [_1] problems',$count).
+                      '</h2>');
+            if ($count > 30) {
+                $r->print('<h3>'.&mt('This will take some time.').'</h3>');
+            }
+            $r->rflush();
+        }
+        #
         my $sortby = $ENV{'form.sortby'};
         $sortby = 'container' if (! defined($sortby) || $sortby =~ /^\s*$/);
         my $plot = $ENV{'form.plot'};
-        &Apache::lonnet::logthis('form.plot = '.$plot);
+        if ($plot eq '' || $plot eq 'none') {
+            undef($plot);
+        }
         if ($sortby eq 'container' && ! defined($plot)) {
+            &output_sequence_statistics($r);
             &output_html_by_sequence($r);
         } else {
             if (defined($plot)) {
-                &Apache::lonnet::logthis('calling plot routine');
                 &make_plot($r,$plot);
             }
             &output_html_stats($r);
+            &output_sequence_statistics($r);
         }
     }
     return;
 }
 
+sub output_sequence_statistics {
+    my ($r) = @_;
+    my $c=$r->connection();
+    $r->print('<h2>'.&mt('Sequence Statistics').'</h2>');
+    $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n".
+              '<table border="0" cellpadding="3">'."\n".
+              '<tr bgcolor="#FFFFE6">');
+    $r->print(&sequence_html_header());
+    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
+        last if ($c->aborted);
+        next if ($seq->{'num_assess'} < 1);
+        &compute_sequence_statistics($seq);
+        $r->print(&sequence_html_output($seq));
+    }
+    $r->print('</table>');
+    $r->print('</table>');
+    $r->rflush();
+    return;
+}
+
+
 ##########################################################
 ##########################################################
 ##
@@ -385,7 +695,6 @@ sub output_html_stats {
     return;
 }
 
-
 sub html_preamble {
     my $Str='';
     $Str .= "<h2>".
@@ -417,6 +726,7 @@ sub statistics_html_table_data {
     my $row = '';
     foreach my $field (@Fields) {
         next if ($options =~ /no $field->{'name'}/);
+        next if ($field->{'selected'} ne 'yes');
         $row .= '<td bgcolor="'.$field->{'color'}.'"';
         if (exists($field->{'align'})) {
             $row .= ' align="'.$field->{'align'}.'"';
@@ -443,6 +753,7 @@ sub statistics_table_header {
     my $header_row;
     foreach my $field (@Fields) {
         next if ($options =~ /no $field->{'name'}/);
+        next if ($field->{'selected'} ne 'yes');
         $header_row .= '<th>';
         if (exists($field->{'sortable'}) && $field->{'sortable'} eq 'yes') {
             $header_row .= '<a href="javascript:'.
@@ -467,6 +778,46 @@ sub statistics_table_header {
     return $header_row;
 }
 
+sub sequence_html_header {
+    my $Str .= '<tr>';
+    foreach my $field (@SeqFields) {
+#        next if ($field->{'selected'} ne 'yes');
+        $Str .= '<th bgcolor="'.$field->{'color'}.'"';
+        $Str .= '>'.$field->{'title'}.'</th>';
+    }
+    $Str .= '</tr>';
+    return $Str;
+}
+
+
+sub sequence_html_output {
+    my ($seq) = @_;
+    my $data = $SeqStat{$seq->{'symb'}};
+#    $SeqStat{$symb}->{'max'}
+#    $SeqStat{$symb}->{'min'}
+#    $SeqStat{$symb}->{'mean'}
+#    $SeqStat{$symb}->{'std'}
+#    $SeqStat{$symb}->{'count'}
+#    $SeqStat{$symb}->{'max_possible'}
+    my $row = '<tr>';
+    foreach my $field (@SeqFields) {
+#        next if ($field->{'selected'} ne 'yes');
+        $row .= '<td bgcolor="'.$field->{'color'}.'"';
+        if (exists($field->{'align'})) {
+            $row .= ' align="'.$field->{'align'}.'"';
+        }
+        $row .= '>';
+        if (exists($field->{'format'})) {
+            $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
+        } else {
+            $row .= $data->{$field->{'name'}};
+        }
+        $row .= '</td>';
+    }
+    $row .= '</tr>'."\n";
+    return $row;
+}
+
 ####################################################
 ####################################################
 ##
@@ -852,6 +1203,7 @@ sub Excel_output {
     # Long Headers
     foreach my $field (@Fields) {
         next if ($field->{'name'} eq 'problem_num');
+        next if ($field->{'selected'} ne 'yes');
         if (exists($field->{'long_title'})) {
             $excel_sheet->write($rows_output,$cols_output++,
                                 $field->{'long_title'});
@@ -863,6 +1215,7 @@ sub Excel_output {
     $cols_output=0;
     # Brief headers
     foreach my $field (@Fields) {
+        next if ($field->{'selected'} ne 'yes');
         next if ($field->{'name'} eq 'problem_num');
         # Use english for excel as I am not sure how well excel handles 
         # other character sets....
@@ -872,6 +1225,7 @@ sub Excel_output {
     foreach my $data (@StatsArray) {
         $cols_output=0;
         foreach my $field (@Fields) {
+            next if ($field->{'selected'} ne 'yes');
             next if ($field->{'name'} eq 'problem_num');
             $excel_sheet->write($rows_output,$cols_output++,
                                 $data->{$field->{'name'}});
@@ -1021,11 +1375,13 @@ sub get_statistics {
     $data->{'title.link'}  = $resource->{'src'}.'?symb='.
         &Apache::lonnet::escape($resource->{'symb'});
     #
-    $data->{'deg_of_disc'} = &compute_discrimination_factor($resource,$part,$sequence);
+    if ($SelectedFields{'deg_of_disc'}) {
+        $data->{'deg_of_disc'} = 
+            &compute_discrimination_factor($resource,$part,$sequence);
+    }
     return $data;
 }
 
-
 ###############################################
 ###############################################
 
@@ -1082,6 +1438,70 @@ sub compute_discrimination_factor {
 
 ###############################################
 ###############################################
+##
+## Compute KR-21
+##
+## To compute KR-21, you need the following information:
+##
+## K=the number of items in your test
+## M=the mean score on the test
+## s=the standard deviation of the scores on your test 
+##
+## then:
+## 
+## KR-21 rk= [K/(K-1)] * [1- (M*(K-M))/(K*s^2))]
+##
+###############################################
+###############################################
+sub compute_sequence_statistics {
+    my ($seq) = @_;
+    my $symb = $seq->{'symb'};
+    my @Resources;
+    foreach my $res (@{$seq->{'contents'}}) {
+        next if ($res->{'type'} ne 'assessment');
+        push (@Resources,$res->{'symb'});
+    }
+    my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
+    #
+    # First compute statistics based on student scores
+    my ($smin,$smax,$sMean,$sSTD,$scount,$sMAX) = 
+        &Apache::loncoursedata::score_stats
+                    (\@Apache::lonstatistics::SelectedSections,
+                     $Apache::lonstatistics::enrollment_status,
+                     \@Resources,$starttime,$endtime,undef);
+    $SeqStat{$symb}->{'title'}  = $seq->{'title'};
+    $SeqStat{$symb}->{'scoremax'}  = $smax;
+    $SeqStat{$symb}->{'scoremin'}  = $smin;
+    $SeqStat{$symb}->{'scoremean'} = $sMean;
+    $SeqStat{$symb}->{'scorestd'}  = $sSTD;
+    $SeqStat{$symb}->{'scorecount'} = $scount;
+    $SeqStat{$symb}->{'max_possible'} = $sMAX;
+    #
+    # Compute statistics based on the number of correct problems
+    # 'correct' is taken to mean 
+    my ($cmin,$cmax,$cMean,$cSTD,$ccount)=
+        &Apache::loncoursedata::count_stats
+        (\@Apache::lonstatistics::SelectedSections,
+         $Apache::lonstatistics::enrollment_status,
+         \@Resources,$starttime,$endtime,undef);
+    my $K = $seq->{'num_assess_parts'};
+    my $kr_21;
+    if ($K > 1 && $cSTD > 0) {
+        $kr_21 =  ($K/($K-1)) * (1 - $cMean*($K-$cMean)/($K*$cSTD**2));
+    } else {
+        $kr_21 = 'nan';
+    }
+    $SeqStat{$symb}->{'countmax'} = $cmax;
+    $SeqStat{$symb}->{'countmin'} = $cmin;
+    $SeqStat{$symb}->{'countstd'} = $cSTD;
+    $SeqStat{$symb}->{'count'} = $ccount;
+    $SeqStat{$symb}->{'items'} = $K;
+    $SeqStat{$symb}->{'KR-21'}=$kr_21;
+
+    return;
+}
+
+
 
 =pod 
 
@@ -1142,111 +1562,6 @@ Number of Students had at least one disc
 
 =cut
 
-
-############################################################
-############################################################
-##
-##  How this all works:
-##     Statistics are computed by calling &get_statistics with the sequence,
-##     resource, and part id to run statistics on.  At various places within
-##     the loops which compute the statistics, as well as before and after 
-##     the entire process, subroutines can be called.  The subroutines are
-##     registered to the following hooks:
-##
-##         hook          subroutine inputs
-##     ----------------------------------------------------------
-##         pre           $r,$count
-##         pre_seq       $r,$count,$seq
-##         pre_res       $r,$count,$seq,$res
-##         calc          $r,$count,$seq,$res,$data
-##         post_res      $r,$count,$seq,$res
-##         post_seq      $r,$count,$seq
-##         post          $r,$count
-##
-##         abort         $r
-##
-##     subroutines will be called in the order in which they are registered.
-##   
-############################################################
-############################################################
-{
-
-my %hooks;
-my $aborted = 0;
-
-sub abort_computation {
-    $aborted = 1;
-}
-
-sub clear_hooks {
-    $aborted = 0;
-    undef(%hooks);
-}
-
-sub register_hook {
-    my ($hookname,$subref)=@_;
-    if ($hookname !~ /^(pre|pre_seq|pre_res|post|post_seq|post_res|calc)$/){
-        return;
-    }
-    if (ref($subref) ne 'CODE') {
-        &Apache::lonnet::logthis('attempt to register hook to non-code: '.
-                                 $hookname,' = '.$subref);
-    } else {
-        if (exists($hooks{$hookname})) {
-            push(@{$hooks{$hookname}},$subref);
-        } else {
-            $hooks{$hookname} = [$subref];
-        }
-    }
-    return;
-}
-
-sub run_hooks {
-    my $context = shift();
-    foreach my $hook (@{$hooks{$context}}) { 
-        if ($aborted && $context ne 'abort') {
-            last;
-        }
-        my $retvalue = $hook->(@_);
-        if (defined($retvalue) && $retvalue eq '0') {
-            $aborted = 1 if (! $aborted);
-        }
-    }
-}
-
-sub run_statistics {
-    my ($r) = @_;
-    my $count = 0;
-    &run_hooks('pre',$r,$count);
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
-        last if ($aborted);
-        next if ($seq->{'num_assess'}<1);
-        &run_hooks('pre_seq',$r,$count,$seq);
-        foreach my $res (@{$seq->{'contents'}}) {
-            last if ($aborted);
-            next if ($res->{'type'} ne 'assessment');
-            &run_hooks('pre_res',$r,$count,$seq,$res);            
-            foreach my $part (@{$res->{'parts'}}) {
-                last if ($aborted);
-                #
-                # This is where all the work happens
-                my $data = &get_statistics($seq,$res,$part,++$count);
-                &run_hooks('calc',$r,$count,$seq,$res,$part,$data); 
-            }
-            &run_hooks('post_res',$r,$count,$seq,$res);
-        }
-        &run_hooks('post_seq',$r,$count,$seq);
-    }
-    if ($aborted) {
-        &run_hooks('abort',$r);
-    } else {
-        &run_hooks('post',$r,$count);
-    }
-    return;
-}
-
-} # End of %hooks scope
-
 ############################################################
 ############################################################