--- loncom/interface/statistics/lonproblemstatistics.pm	2004/06/16 16:22:52	1.89
+++ loncom/interface/statistics/lonproblemstatistics.pm	2006/05/01 19:29:13	1.107
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: lonproblemstatistics.pm,v 1.89 2004/06/16 16:22:52 matthew Exp $
+# $Id: lonproblemstatistics.pm,v 1.107 2006/05/01 19:29:13 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -50,7 +50,7 @@ Excel files, and plots.
 package Apache::lonproblemstatistics;
 
 use strict;
-use Apache::lonnet();
+use Apache::lonnet;
 use Apache::loncommon();
 use Apache::lonhtmlcommon;
 use Apache::loncoursedata;
@@ -231,6 +231,17 @@ my @Fields = (
              selectable => 'yes',
              defaultselected => 'yes',
            },
+           { name   => 'tries_per_correct',
+             title  => 'tries/correct',
+             align  => 'right',
+             color  => '#FFDDDD',
+             format => '%4.1f',
+             sortable  => 'yes',
+             graphable => 'yes',
+             long_title => 'Tries per Correct Answer',
+             selectable => 'yes',
+             defaultselected => 'yes',
+           },
            { name   => 'num_wrong',
              title  => '#Wrng',
              align  => 'right',
@@ -238,6 +249,17 @@ my @Fields = (
              format => '%4.1f',
              sortable  => 'yes',
              graphable => 'yes',
+             long_title => 'Number of students whose final answer is wrong',
+             selectable => 'yes',
+             defaultselected => 'yes',
+           },
+           { name   => 'per_wrong',
+             title  => '%Wrng',
+             align  => 'right',
+             color  => '#FFDDDD',
+             format => '%4.1f',
+             sortable  => 'yes',
+             graphable => 'yes',
              long_title => 'Percent of students whose final answer is wrong',
              selectable => 'yes',
              defaultselected => 'yes',
@@ -309,6 +331,40 @@ my @Fields = (
 #             selectable => 'no',
 #             defaultselected => 'yes',
 #            },
+##   maxtries included for research purposes.  Commented out most of the time.
+#           { name => 'maxtries',
+#             title => 'Maxtries',
+#             align => 'left',
+#             color => '#FFFFFF',
+#             sortable => 'no',
+#             graphable => 'no',
+#             long_title => 'Maximum number of tries',
+#             selectable => 'no',
+#             defaultselected => 'yes',
+#            },
+##   hinttries included for research purposes.  Commented out most of the time.
+#           { name => 'hinttries',
+#             title => 'hinttries',
+#             align => 'left',
+#             color => '#FFFFFF',
+#             sortable => 'no',
+#             graphable => 'no',
+#             long_title => 'Number of tries before a hint appears',
+#             selectable => 'no',
+#             defaultselected => 'yes',
+#            },
+#
+##   problem weight for instructor
+           { name => 'weight',
+             title => 'weight',
+             align => 'right',
+             color => '#FFFFFF',
+             sortable => 'no',
+             graphable => 'no',
+             long_title => 'Problem weight (for instructor)',
+             selectable => 'yes',
+             defaultselected => 'yes',
+            },
 );
 
 my @SeqFields = (
@@ -460,35 +516,35 @@ my %SelectedFields;
 sub parse_field_selection {
     #
     # Pull out the defaults
-    if (! defined($ENV{'form.fieldselections'})) {
-        $ENV{'form.fieldselections'} = [];
+    if (! defined($env{'form.fieldselections'})) {
+        $env{'form.fieldselections'} = [];
         foreach my $field (@Fields) {
             next if ($field->{'selectable'} ne 'yes');
             if ($field->{'defaultselected'} eq 'yes') {
-                push(@{$ENV{'form.fieldselections'}},$field->{'name'});
+                push(@{$env{'form.fieldselections'}},$field->{'name'});
             }
         }
     }
     #
     # Make sure the data we are plotting is there
     my %NeededFields;
-    if (exists($ENV{'form.plot'}) && $ENV{'form.plot'} ne '' &&
-        $ENV{'form.plot'} ne 'none') {
-        if ($ENV{'form.plot'} eq 'degrees') {
+    if (exists($env{'form.plot'}) && $env{'form.plot'} ne '' &&
+        $env{'form.plot'} ne 'none') {
+        if ($env{'form.plot'} eq 'degrees') {
             $NeededFields{'deg_of_diff'}++;
             $NeededFields{'deg_of_disc'}++;
-        } elsif ($ENV{'form.plot'} eq 'tries statistics') {
+        } elsif ($env{'form.plot'} eq 'tries statistics') {
             $NeededFields{'mean_tries'}++;
             $NeededFields{'std_tries'}++;
             $NeededFields{'problem_num'}++;
         } else {
-            $NeededFields{$ENV{'form.plot'}}++;
+            $NeededFields{$env{'form.plot'}}++;
         }
     }
     #
     # This should not happen, but in case it does...
-    if (ref($ENV{'form.fieldselections'}) ne 'ARRAY') {
-        $ENV{'form.fieldselections'} = [$ENV{'form.fieldselections'}];
+    if (ref($env{'form.fieldselections'}) ne 'ARRAY') {
+        $env{'form.fieldselections'} = [$env{'form.fieldselections'}];
     }
     #
     # Set the field data and the selected fields (for easier checking)
@@ -503,7 +559,7 @@ sub parse_field_selection {
             $field->{'selected'} = 'yes';
             $SelectedFields{$field->{'name'}}++;
         }
-        foreach my $selection (@{$ENV{'form.fieldselections'}}) {
+        foreach my $selection (@{$env{'form.fieldselections'}}) {
             if ($selection eq $field->{'name'} || $selection eq 'all') {
                 $field->{'selected'} = 'yes';
                 $SelectedFields{$field->{'name'}}++;
@@ -552,8 +608,8 @@ sub CreateInterface {
     &parse_field_selection();
     #
     my $Str = '';
-    $Str .= &Apache::lonhtmlcommon::breadcrumbs
-        (undef,'Overall Problem Statistics','Statistics_Overall_Key');
+    $Str .= &Apache::lonhtmlcommon::breadcrumbs('Overall Problem Statistics',
+						'Statistics_Overall_Key');
     $Str .= '<table cellspacing="5">'."\n";
     $Str .= '<tr>';
     $Str .= '<td align="center"><b>'.&mt('Sections').'</b></td>';
@@ -570,16 +626,7 @@ sub CreateInterface {
     $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
     $Str .= '</td><td align="center">';
     #
-    my $only_seq_with_assessments = sub { 
-        my $s=shift;
-        if ($s->{'num_assess'} < 1) { 
-            return 0;
-        } else { 
-            return 1;
-        }
-    };
-    $Str .= &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
-                                              $only_seq_with_assessments);
+    $Str .= &Apache::lonstatistics::map_select('Maps','multiple,all',5);
     $Str .= '</td><td>'.&field_selection_input();
     $Str .= '</td></tr>'."\n";
     $Str .= '</table>'."\n";
@@ -611,8 +658,18 @@ Main interface to problem statistics.
 
 ###############################################
 ###############################################
+my $navmap;
+my @sequences;
+
+sub clean_up {
+    undef($navmap);
+    undef(@sequences);
+}
+
 sub BuildProblemStatisticsPage {
     my ($r,$c)=@_;
+    undef($navmap);
+    undef(@sequences);
     #
     my %Saveable_Parameters = ('Status' => 'scalar',
                                'statsoutputmode' => 'scalar',
@@ -634,7 +691,7 @@ sub BuildProblemStatisticsPage {
     # Finally let the user know we are here
     my $interface = &CreateInterface($r);
     $r->print($interface);
-    $r->print('<input type="hidden" name="sortby" value="'.$ENV{'form.sortby'}.
+    $r->print('<input type="hidden" name="sortby" value="'.$env{'form.sortby'}.
               '" />');
     #
     my @CacheButtonHTML = 
@@ -645,7 +702,7 @@ sub BuildProblemStatisticsPage {
     }
     #
     $r->print($Str);
-    if (! exists($ENV{'form.firstrun'})) {
+    if (! exists($env{'form.firstrun'})) {
         $r->print('<h3>'.
                   &mt('Press "Generate Statistics" when you are ready.').
                   '</h3><p>'.
@@ -653,6 +710,7 @@ sub BuildProblemStatisticsPage {
                       'for the first analysis.  Future analysis this session '.
                       ' will not have this delay.').
                   '</p>');
+	&clean_up();
         return;
     }
     $r->rflush();
@@ -661,15 +719,31 @@ sub BuildProblemStatisticsPage {
     # it does not slow things down noticably.
     &Apache::loncoursedata::populate_weight_table();
     #
-    if (exists($ENV{'form.Excel'})) {
+    ($navmap,@sequences) = 
+        &Apache::lonstatistics::selected_sequences_with_assessments();
+    if (! ref($navmap)) {
+        $r->print('<h1>'.&mt('A course-wide error occured.').'</h1>'.
+                  '<h3>'.$navmap.'</h3>');
+	&clean_up();
+        return;
+    }
+    if (exists($env{'form.Excel'})) {
+        $r->print('<h4>'.
+                  &Apache::lonstatistics::section_and_enrollment_description().
+                  '</h4>');
         &Excel_output($r);
     } else { 
         $r->print('<input type="submit" name="Excel" value="'.
                   &mt('Produce Excel Output').'" />'.'&nbsp;'x5);
         $r->rflush();
+        $r->print('<h4>'.
+                  &Apache::lonstatistics::section_and_enrollment_description().
+                  '</h4>');
         my $count = 0;
-        foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
-            $count += $seq->{'num_assess_parts'};
+        foreach my $seq (@sequences) {
+            my @resources = 
+                &Apache::lonstathelpers::get_resources($navmap,$seq);
+            $count += scalar(@resources);
         }
         if ($count > 10) {
             $r->print('<h2>'.
@@ -681,9 +755,9 @@ sub BuildProblemStatisticsPage {
             $r->rflush();
         }
         #
-        my $sortby = $ENV{'form.sortby'};
+        my $sortby = $env{'form.sortby'};
         $sortby = 'container' if (! defined($sortby) || $sortby =~ /^\s*$/);
-        my $plot = $ENV{'form.plot'};
+        my $plot = $env{'form.plot'};
         if ($plot eq '' || $plot eq 'none') {
             undef($plot);
         }
@@ -698,20 +772,22 @@ sub BuildProblemStatisticsPage {
             &output_sequence_statistics($r);
         }
     }
+    &clean_up();
     return;
 }
 
 sub output_sequence_statistics {
     my ($r) = @_;
     my $c=$r->connection();
-    $r->print('<h2>'.&mt('Sequence Statistics').'</h2>');
+    $r->print('<h2>'.&mt('Sequence Statistics').
+	      &Apache::loncommon::help_open_topic('Statistics_Sequence').
+	      '</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()) {
+    foreach my $seq (@sequences) { 
         last if ($c->aborted);
-        next if ($seq->{'num_assess'} < 1);
         &compute_sequence_statistics($seq);
         $r->print(&sequence_html_output($seq));
     }
@@ -734,10 +810,9 @@ sub output_html_by_sequence {
     my $c = $r->connection();
     $r->print(&html_preamble());
     #
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
+    foreach my $seq (@sequences) {
         last if ($c->aborted);
-        next if ($seq->{'num_assess'} < 1);
-        $r->print("<h3>".$seq->{'title'}."</h3>".
+        $r->print("<h3>".$seq->compTitle."</h3>".
                   '<table border="0"><tr><td bgcolor="#777777">'."\n".
                   '<table border="0" cellpadding="3">'."\n".
                   '<tr bgcolor="#FFFFE6">'.
@@ -758,7 +833,7 @@ sub output_html_stats {
     my ($r)=@_;
     &compute_all_statistics($r);
     $r->print(&html_preamble());
-    &sort_data($ENV{'form.sortby'});
+    &sort_data($env{'form.sortby'});
     #
     my $count=0;
     foreach my $data (@StatsArray) {
@@ -780,7 +855,7 @@ sub output_html_stats {
 sub html_preamble {
     my $Str='';
     $Str .= "<h2>".
-        $ENV{'course.'.$ENV{'request.course.id'}.'.description'}.
+        $env{'course.'.$env{'request.course.id'}.'.description'}.
         "</h2>\n";
     my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
     if (defined($starttime) || defined($endtime)) {
@@ -817,7 +892,7 @@ sub statistics_html_table_data {
         if (exists($field->{'special'}) && $field->{'special'} eq 'link') {
             $row .= '<a href="'.$data->{$field->{'name'}.'.link'}.'">';
         }
-        if (exists($field->{'format'})) {
+        if (exists($field->{'format'}) && $data->{$field->{'name'}} !~ /[A-Z]/i) {
             $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
         } else {
             $row .= $data->{$field->{'name'}};
@@ -874,7 +949,7 @@ sub sequence_html_header {
 
 sub sequence_html_output {
     my ($seq) = @_;
-    my $data = $SeqStat{$seq->{'symb'}};
+    my $data = $SeqStat{$seq->symb};
     my $row = '<tr>';
     foreach my $field (@SeqFields) {
         next if ($field->{'selected'} ne 'yes');
@@ -904,7 +979,7 @@ sub sequence_html_output {
 sub make_plot {
     my ($r,$plot) = @_;
     &compute_all_statistics($r);
-    &sort_data($ENV{'form.sortby'});
+    &sort_data($env{'form.sortby'});
     if ($plot eq 'degrees') {
         &degrees_plot($r);
     } elsif ($plot eq 'tries statistics') {
@@ -1158,8 +1233,8 @@ END
 sub plot_dropdown {
     my $current = '';
     #
-    if (defined($ENV{'form.plot'})) {
-        $current = $ENV{'form.plot'};
+    if (defined($env{'form.plot'})) {
+        $current = $env{'form.plot'};
     }
     #
     my @Additional_Plots = (
@@ -1203,40 +1278,21 @@ sub Excel_output {
     &compute_all_statistics($r);
     my $c = $r->connection;
     return if ($c->aborted());
+    #
+    my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
     ##
     ## Create the excel workbook
-    my $filename = '/prtspool/'.
-        $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
-        time.'_'.rand(1000000000).'.xls';
-    my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
-    #
-    # Create sheet
-    my $excel_workbook = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
-    #
-    # Check for errors
-    if (! defined($excel_workbook)) {
-        $r->log_error("Error creating excel spreadsheet $filename: $!");
-        $r->print(&mt("Problems creating new Excel file.  ".
-                  "This error has been logged.  ".
-                  "Please alert your LON-CAPA administrator."));
-        return 0;
-    }
-    #
-    # The excel spreadsheet stores temporary data in files, then put them
-    # together.  If needed we should be able to disable this (memory only).
-    # The temporary directory must be specified before calling 'addworksheet'.
-    # File::Temp is used to determine the temporary directory.
-    $excel_workbook->set_tempdir($Apache::lonnet::tmpdir);
+    my ($excel_workbook,$filename,$format) =
+        &Apache::loncommon::create_workbook($r);
+    return if (! defined($excel_workbook));
     #
     # Add a worksheet
-    my $sheetname = $ENV{'course.'.$ENV{'request.course.id'}.'.description'};
+    my $sheetname = $env{'course.'.$env{'request.course.id'}.'.description'};
     if (length($sheetname) > 31) {
         $sheetname = substr($sheetname,0,31);
     }
     my $excel_sheet = $excel_workbook->addworksheet(
         &Apache::loncommon::clean_excel_name($sheetname));
-    #
-    my $format = &Apache::loncommon::define_excel_formats($excel_workbook);
     ##
     ## Begin creating excel sheet
     ##
@@ -1244,17 +1300,16 @@ sub Excel_output {
     #
     # Put the course description in the header
     $excel_sheet->write($rows_output,$cols_output++,
-                   $ENV{'course.'.$ENV{'request.course.id'}.'.description'},
+                   $env{'course.'.$env{'request.course.id'}.'.description'},
                         $format->{'h1'});
     $cols_output += 3;
     #
     # Put a description of the sections listed
     my $sectionstring = '';
     $excel_sheet->write($rows_output,$cols_output++,
-                        &Apache::lonstathelpers::sections_description
-                            (@Apache::lonstatistics::SelectedSections),
+                        &Apache::lonstatistics::section_and_enrollment_description('plaintext'),
                         $format->{'h3'});
-    $cols_output += scalar(@Apache::lonstatistics::SelectedSections);
+    $cols_output += scalar(&Apache::lonstatistics::get_selected_sections());
     #
     # Time restrictions
     my $time_string;
@@ -1286,9 +1341,8 @@ sub Excel_output {
     ## 
     &write_headers($excel_sheet,$format,\$rows_output,\$cols_output,
                    \@SeqFields);
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
-        next if ($seq->{'num_assess'} < 1);
-        my $data = $SeqStat{$seq->{'symb'}};
+    foreach my $seq (@sequences) {
+        my $data = $SeqStat{$seq->symb};
         $cols_output=0;
         foreach my $field (@SeqFields) {
             next if ($field->{'selected'} ne 'yes');
@@ -1384,10 +1438,9 @@ sub write_headers {
 sub compute_statistics_on_sequence {
     my ($seq) = @_;
     my @Data;
-    foreach my $res (@{$seq->{'contents'}}) {
-        next if ($res->{'type'} ne 'assessment');
-        foreach my $part (@{$res->{'parts'}}) {
-            next if ($res->{'partdata'}->{$part}->{'Survey'});
+    foreach my $res (&Apache::lonstathelpers::get_resources($navmap,$seq)) {
+        foreach my $part (@{$res->parts}) {
+            next if ($res->is_survey($part));
             #
             # This is where all the work happens
             my $data = &get_statistics($seq,$res,$part,scalar(@StatsArray)+1);
@@ -1405,9 +1458,8 @@ sub compute_all_statistics {
         return;
     }
     my $c = $r->connection;
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
+    foreach my $seq (@sequences) {
         last if ($c->aborted);
-        next if ($seq->{'num_assess'} < 1);
         &compute_sequence_statistics($seq);
         &compute_statistics_on_sequence($seq);
     }
@@ -1494,20 +1546,20 @@ sub get_statistics {
     my ($sequence,$resource,$part,$problem_num) = @_;
     #
     my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
-    my $symb = $resource->{'symb'};
-    my $courseid = $ENV{'request.course.id'};
+    my $symb = $resource->symb;
+    my $courseid = $env{'request.course.id'};
     #
     my $data = &Apache::loncoursedata::get_problem_statistics
-                        (\@Apache::lonstatistics::SelectedSections,
+                        ([&Apache::lonstatistics::get_selected_sections()],
                          $Apache::lonstatistics::enrollment_status,
                          $symb,$part,$courseid,$starttime,$endtime);
     $data->{'symb'}        = $symb;
     $data->{'part'}        = $part;
     $data->{'problem_num'} = $problem_num;
-    $data->{'container'}   = $sequence->{'title'};
-    $data->{'title'}       = $resource->{'title'};
-    $data->{'title.link'}  = $resource->{'src'}.'?symb='.
-        &Apache::lonnet::escape($resource->{'symb'});
+    $data->{'container'}   = $sequence->compTitle;
+    $data->{'title'}       = $resource->compTitle;
+    $data->{'title.link'}  = $resource->src.'?symb='.
+        &Apache::lonnet::escape($resource->symb);
     #
     if ($SelectedFields{'deg_of_disc'}) {
         $data->{'deg_of_disc'} = 
@@ -1516,12 +1568,12 @@ sub get_statistics {
     #
     # Store in metadata if computations were done for all students
     if ($data->{'num_students'} > 1) {
-        my @Sections = @Apache::lonstatistics::SelectedSections;
+        my @Sections = &Apache::lonstatistics::get_selected_sections();
         my $sections = '"'.join(' ',@Sections).'"';
         $sections =~ s/&+/_/g;  # Ensure no special characters
         $data->{'sections'}=$sections;
-        $data->{'course'} = $ENV{'request.course.id'};
-        my $urlres=(&Apache::lonnet::decode_symb($resource->{'symb'}))[2];
+        $data->{'course'} = $env{'request.course.id'};
+        my $urlres=(&Apache::lonnet::decode_symb($resource->symb))[2];
         $data->{'urlres'}=$urlres;
         my %storestats = 
             &LONCAPA::lonmetadata::dynamic_metadata_storage($data);
@@ -1529,11 +1581,20 @@ sub get_statistics {
         &Apache::lonnet::put('nohist_resevaldata',\%storestats,$dom,$user);
     }
     #
+    $data->{'tries_per_correct'} = $data->{'tries'} / 
+        ($data->{'num_solved'}+0.1);
+    #
     # Get the due date for research purposes (commented out most of the time)
 #    $data->{'duedate'} = 
 #        &Apache::lonnet::EXT('resource.'.$part.'.duedate',$symb);
 #    $data->{'opendate'} = 
 #        &Apache::lonnet::EXT('resource.'.$part.'.opendate',$symb);
+#    $data->{'maxtries'} = 
+#        &Apache::lonnet::EXT('resource.'.$part.'.maxtries',$symb);
+#    $data->{'hinttries'} =
+#        &Apache::lonnet::EXT('resource.'.$part.'.hinttries',$symb);
+    $data->{'weight'} =
+        &Apache::lonnet::EXT('resource.'.$part.'.weight',$symb);
 #    $data->{'resptypes'} = join(',',@{$resource->{'partdata'}->{$part}->{'ResponseTypes'}});
     return $data;
 }
@@ -1554,11 +1615,12 @@ Returns: integer between -1 and 1
 ###############################################
 ###############################################
 sub compute_discrimination_factor {
-    my ($resource,$part,$sequence) = @_;
+    my ($resource,$part,$seq) = @_;
+    my $symb = $resource->symb;
     my @Resources;
-    foreach my $res (@{$sequence->{'contents'}}) {
-        next if ($res->{'symb'} eq $resource->{'symb'});
-        push (@Resources,$res->{'symb'});
+    foreach my $res (&Apache::lonstathelpers::get_resources($navmap,$seq)){
+        next if ($res->symb eq $symb);
+        push (@Resources,$res->symb);
     }
     #
     # rank
@@ -1566,9 +1628,9 @@ sub compute_discrimination_factor {
     my $ranking = 
         &Apache::loncoursedata::rank_students_by_scores_on_resources
         (\@Resources,
-         \@Apache::lonstatistics::SelectedSections,
+         [&Apache::lonstatistics::get_selected_sections()],
          $Apache::lonstatistics::enrollment_status,undef,
-         $starttime,$endtime);
+         $starttime,$endtime, $symb);
     #
     # compute their percent scores on the problems in the sequence,
     my $number_to_grab = int(scalar(@{$ranking})/4);
@@ -1578,12 +1640,16 @@ sub compute_discrimination_factor {
     my @TopSet    = 
         map { 
             $_->[&Apache::loncoursedata::RNK_student()]; 
-          } @{$ranking}[($num_students-$number_to_grab)..($num_students-1)];
+          } @{$ranking}[-$number_to_grab..0];
+    if (! @BottomSet || (@BottomSet == 1 && $BottomSet[0] eq '') ||
+        ! @TopSet    || (@TopSet    == 1 && $TopSet[0]    eq '')) {
+        return 'nan';
+    }
     my ($bottom_sum,$bottom_max) = 
-        &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@BottomSet,
+        &Apache::loncoursedata::get_sum_of_scores($symb,$part,\@BottomSet,
                                                   undef,$starttime,$endtime);
     my ($top_sum,$top_max) = 
-        &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@TopSet,
+        &Apache::loncoursedata::get_sum_of_scores($symb,$part,\@TopSet,
                                                   undef,$starttime,$endtime);
     my $deg_of_disc;
     if ($top_max == 0 || $bottom_max==0) {
@@ -1615,21 +1681,22 @@ sub compute_discrimination_factor {
 ###############################################
 sub compute_sequence_statistics {
     my ($seq) = @_;
-    my $symb = $seq->{'symb'};
+    my $symb = $seq->symb;
     my @Resources;
-    foreach my $res (@{$seq->{'contents'}}) {
-        next if ($res->{'type'} ne 'assessment');
-        push (@Resources,$res->{'symb'});
+    my $part_count;
+    foreach my $res (&Apache::lonstathelpers::get_resources($navmap,$seq)) {
+        push (@Resources,$res->symb);
+        $part_count += scalar(@{$res->parts});
     }
     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::get_selected_sections()],
                      $Apache::lonstatistics::enrollment_status,
                      \@Resources,$starttime,$endtime,undef);
-    $SeqStat{$symb}->{'title'}  = $seq->{'title'};
+    $SeqStat{$symb}->{'title'}  = $seq->compTitle;
     $SeqStat{$symb}->{'scoremax'}  = $smax;
     $SeqStat{$symb}->{'scoremin'}  = $smin;
     $SeqStat{$symb}->{'scoremean'} = $sMean;
@@ -1641,10 +1708,10 @@ sub compute_sequence_statistics {
     # 'correct' is taken to mean 
     my ($cmin,$cmax,$cMean,$cSTD,$ccount)=
         &Apache::loncoursedata::count_stats
-        (\@Apache::lonstatistics::SelectedSections,
+        ([&Apache::lonstatistics::get_selected_sections()],
          $Apache::lonstatistics::enrollment_status,
          \@Resources,$starttime,$endtime,undef);
-    my $K = $seq->{'num_assess_parts'};
+    my $K = $part_count;
     my $kr_21;
     if ($K > 1 && $cSTD > 0) {
         $kr_21 =  ($K/($K-1)) * (1 - $cMean*($K-$cMean)/($K*$cSTD**2));