';
- $Ptr .= &ProblemStatisticsLegend();
- $r->print($Ptr);
- $r->rflush();
+Main interface to problem statistics.
- untie(%cache);
- &Create_PrgWin($r);
- my $count=0;
- foreach (@$students) {
- &Update_PrgWin(scalar(@$students),$count,$_,$r);
- my $courseData =
- &Apache::loncoursedata::DownloadCourseInformation($_, $courseID);
- last if ($c->aborted());
- if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
- &Apache::loncoursedata::ProcessStudentData(\%cache,
- $courseData, $_);
- untie(%cache);
- }
- $count++;
- }
- &Close_PrgWin($r);
- if($c->aborted()) { return; }
-
- unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
- return 'Unable to tie database.';
- }
-
- my %Header = (0,"Homework Sets Order",1,"#Stdnts",2,"Tries",3,"Mod",
- 4,"Mean",5,"#YES",6,"#yes",7,"%Wrng",8,"DoDiff",
- 9,"S.D.",10,"Skew.",11,"D.F.1st",12,"D.F.2nd", 13, "Disc.");
- my $color=&setbgcolor(0);
-
- my $state=$ENV{'form.ProblemStatisticsHeading'};
-
- my $TempCache;
-
- if ($state) {
- $TempCache=&CacheStatisticsTable($state,\%cache,\%Header,
- $r,$color);
- } else {
- my %discriminant=();
- my @list=();
- my %Discuss=&Apache::loncoursedata::LoadDiscussion($courseID);
- my $index=0;
- foreach (@$students) {
- $index++;
- &ExtractStudentData(\%cache, $_, \@list,\%Discuss, $r,
- \%discriminant);
- }
- my ($upper, $lower) = &Discriminant(\%discriminant,$r);
- $TempCache= &BuildStatisticsTable(\%cache, $upper, $lower,
- \@list, \%Header, $students,
- $r, $color);
- }
- untie(%cache);
-
- foreach (keys %$TempCache) {
- last if ($c->aborted());
- if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
- $cache{$_}=$TempCache->{$_};
-
- untie(%cache);
- }
- }
- if($c->aborted()) { return; }
- untie(%cache);
-}
-
-
-#---- Problem Statistics Web Page ---------------------------------------
-
-sub CreateProblemStatisticsTableHeading {
- my ($displayFormat,$sequenceSource,$sequenceTitle,$headings,$r)=@_;
- if($displayFormat eq 'Display CSV Format') {
- $r->print(' "'.$sequenceTitle.'","');
- $r->print($sequenceSource.'"');
- return;
- }
- if ($sequenceSource eq 'Sorted by: ') {
- $r->print(' '.$sequenceSource.$sequenceTitle.'');
+=cut
+
+###############################################
+###############################################
+sub BuildProblemStatisticsPage {
+ my ($r,$c)=@_;
+ #
+ my %Saveable_Parameters = ('Status' => 'scalar',
+ 'statsoutputmode' => 'scalar',
+ 'Section' => 'array',
+ 'StudentData' => 'array',
+ 'Maps' => 'array');
+ &Apache::loncommon::store_course_settings('statistics',
+ \%Saveable_Parameters);
+ &Apache::loncommon::restore_course_settings('statistics',
+ \%Saveable_Parameters);
+ #
+ &Apache::lonstatistics::PrepareClasslist();
+ #
+ # Clear the package variables
+ undef(@StatsArray);
+ #
+ # Finally let the user know we are here
+ my $interface = &CreateInterface();
+ $r->print($interface);
+ $r->print('');
+ #
+ if (! exists($ENV{'form.statsfirstcall'})) {
+ $r->print('');
+ $r->print('
'.
+ &mt('Press "Generate Statistics" when you are ready.').
+ '
'.
+ &mt('It may take some time to update the student data '.
+ 'for the first analysis. Future analysis this session '.
+ ' will not have this delay.').
+ '
\n";
+ my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
+ if (defined($starttime) || defined($endtime)) {
+ # Inform the user what the time limits on the data are.
+ $Str .= '
'.&mt('Statistics on submissions from [_1] to [_2]',
+ &Apache::lonlocal::locallocaltime($starttime),
+ &Apache::lonlocal::locallocaltime($endtime)
+ ).'
';
+ }
+ $Str .= "
".&mt('Compiled on [_1]',
+ &Apache::lonlocal::locallocaltime(time))."
";
+ return $Str;
}
-
-# ------ Dump the Student's DB file and handling the data for statistics table
-sub ExtractStudentData {
- my ($cache,$name,$list,$Discuss,$r,$discriminant)=@_;
- my $totalTries = 0;
- my $totalAwarded = 0;
- my $spent=0;
- my $spent_yes=0;
- my $TotDiscuss=0;
- my $TotalOpend = 0;
- my $ProbSolved = 0;
- my $ProbTot = 0;
- my $TotFirst = 0;
- my $TimeTot = 0;
- my $Discussed=0;
- my $discrim='';
- my $tempSequenceOrder=100;
-
-#$Apache::lonxml::debug=1;
-#&Apache::lonhomework::showhash(%$cache);
-#$Apache::lonxml::debug=0;
-
- foreach my $sequence (split(':', $cache->{'orderedSequences'})) {
- my $tempProblemOrder=100;
- if($cache->{'ProblemStatisticsMaps'} ne 'All Maps' &&
- $cache->{'ProblemStatisticsMaps'} ne $cache->{$sequence.':title'}) {
- next;
- }
- $tempSequenceOrder++;
- foreach my $problemID (split(':', $cache->{$sequence.':problems'})) {
- my $problem = $cache->{$problemID.':problem'};
- my $LatestVersion = $cache->{$name.':version:'.$problem};
- # Output dashes for all the parts of this problem if there
- # is no version information about the current problem.
- #if(!$LatestVersion) {
- # foreach my $part (split(/\:/,$cache->{$sequence.':'.
- # $problemID.
- # ':parts'})) {
- # $codes .= "-,";
- # $attempts .= "0,";
- # }
- # next;
- #}
-
- my %partData=undef;
- $partData{'count'}=0;
- # Initialize part data, display skips correctly
- # Skip refers to when a student made no submissions on that
- # part/problem.
- foreach my $part (split(/\:/,$cache->{$sequence.':'.
- $problemID.
- ':parts'})) {
- $tempProblemOrder++;
- $partData{'count'}++;
- $partData{$part.':order'}=$tempProblemOrder;
- $partData{$part.':tries'}=0;
- $partData{$part.':code'}='-';
+###############################################
+###############################################
+##
+## Misc HTML output routines
+##
+###############################################
+###############################################
+sub statistics_html_table_data {
+ my ($data,$options) = @_;
+ my $row = '';
+ foreach my $field (@Fields) {
+ next if ($options =~ /no $field->{'name'}/);
+ $row .= '
');
+ ##
+ ## Compute the statistics
+ &compute_all_statistics($r);
+ my $c = $r->connection;
+ return if ($c->aborted());
+ ##
+ ## 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);
+ #
+ # Add a worksheet
+ 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));
+ ##
+ ## Begin creating excel sheet
+ ##
+ my ($rows_output,$cols_output) = (0,0);
+ #
+ # Put the course description in the header
+ $excel_sheet->write($rows_output,$cols_output++,
+ $ENV{'course.'.$ENV{'request.course.id'}.'.description'});
+ $cols_output += 3;
+ #
+ # Put a description of the sections listed
+ my $sectionstring = '';
+ my @Sections = @Apache::lonstatistics::SelectedSections;
+ if (scalar(@Sections) > 1) {
+ if (scalar(@Sections) > 2) {
+ my $last = pop(@Sections);
+ $sectionstring = "Sections ".join(', ',@Sections).', and '.$last;
+ } else {
+ $sectionstring = "Sections ".join(' and ',@Sections);
+ }
} else {
- $Ptr="\n".'
'.
- "\n".'
'.($RealIdx+1).'
'.
- "\n".'
'.$Temp.'
'.
- "\n".'
'.$StdNo.'
'.
- "\n".'
'.$TotalTries.'
'.
- "\n".'
'.$MxTries.'
'.
- "\n".'
'.$Avg.'
'.
- "\n".'
'.$YES.'
'.
- "\n".'
'.$Override.'
'.
- "\n".'
'.$Wrng.'
'.
- "\n".'
'.$DoD.'
'.
- "\n".'
'.$SD.'
'.
- "\n".'
'.$Sk.'
'.
- "\n".'
'.$_D1.'
'.
- "\n".'
'.$_D2.'
'.
- "\n".'
'.$DiscNo.'
';
- $r->print("\n".$Ptr.'
' );
- }
- $GraphDat->{'GraphGif:'.$RealIdx}=$DoD.':'.$Wrng;
+ if ($Sections[0] eq 'all') {
+ $sectionstring = "All sections";
+ } else {
+ $sectionstring = "Section ".$Sections[0];
+ }
+ }
+ $excel_sheet->write($rows_output,$cols_output++,$sectionstring);
+ $cols_output += scalar(@Sections);
+ #
+ # Time restrictions
+ my $time_string;
+ if (defined($starttime)) {
+ # call localtime but not lonlocal:locallocaltime because excel probably
+ # cannot handle localized text. Probably.
+ $time_string .= 'Data collected from '.localtime($time_string);
+ if (defined($endtime)) {
+ $time_string .= ' to '.localtime($endtime);
+ }
+ $time_string .= '.';
+ } elsif (defined($endtime)) {
+ # See note above about lonlocal:locallocaltime
+ $time_string .= 'Data collected before '.localtime($endtime).'.';
+ }
+ #
+ # Put the date in there too
+ $excel_sheet->write($rows_output,$cols_output++,
+ 'Compiled on '.localtime(time));
+ #
+ $rows_output++;
+ $cols_output=0;
+ #
+ # Long Headers
+ foreach my $field (@Fields) {
+ next if ($field->{'name'} eq 'problem_num');
+ if (exists($field->{'long_title'})) {
+ $excel_sheet->write($rows_output,$cols_output++,
+ $field->{'long_title'});
+ } else {
+ $excel_sheet->write($rows_output,$cols_output++,'');
+ }
+ }
+ $rows_output++;
+ $cols_output=0;
+ # Brief headers
+ foreach my $field (@Fields) {
+ next if ($field->{'name'} eq 'problem_num');
+ # Use english for excel as I am not sure how well excel handles
+ # other character sets....
+ $excel_sheet->write($rows_output,$cols_output++,$field->{'title'});
+ }
+ $rows_output++;
+ foreach my $data (@StatsArray) {
+ $cols_output=0;
+ foreach my $field (@Fields) {
+ next if ($field->{'name'} eq 'problem_num');
+ $excel_sheet->write($rows_output,$cols_output++,
+ $data->{$field->{'name'}});
+ }
+ $rows_output++;
+ }
+ #
+ $excel_workbook->close();
+ #
+ # Tell the user where to get their excel file
+ $r->print(' '.
+ ''.
+ &mt('Your Excel Spreadsheet').''."\n");
+ $r->rflush();
+ return;
}
-
-# For loading the colored table for display or un-colored for print
-sub setbgcolor {
- my $PrintTable=shift;
- my %color;
- if ($PrintTable){
- $color{"gb"}="#FFFFFF";
- $color{"red"}="#FFFFFF";
- $color{"yellow"}="#FFFFFF";
- $color{"green"}="#FFFFFF";
- $color{"purple"}="#FFFFFF";
- } else {
- $color{"gb"}="#DDFFFF";
- $color{"red"}="#FFDDDD";
- $color{"yellow"}="#EEFFCC";
- $color{"green"}="#DDFFDD";
- $color{"purple"}="#FFDDFF";
- }
-
- return \%color;
-}
-
-sub ProblemStatisticsButtons {
- my ($displayFormat)=@_;
-
- my $Ptr = '
';
- $Ptr .= '{'contents'}}) {
+ next if ($res->{'type'} ne 'assessment');
+ foreach my $part (@{$res->{'parts'}}) {
+ #
+ # This is where all the work happens
+ my $data = &get_statistics($seq,$res,$part,scalar(@StatsArray)+1);
+ push (@Data,$data);
+ push (@StatsArray,$data);
+ }
}
- $Ptr .= '
';
+ return @Data;
+}
- return $Ptr;
+sub compute_all_statistics {
+ my ($r) = @_;
+ if (@StatsArray > 0) {
+ # Assume we have already computed the statistics
+ return;
+ }
+ my $c = $r->connection;
+ foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
+ last if ($c->aborted);
+ next if ($seq->{'num_assess'} < 1);
+ &compute_statistics_on_sequence($seq);
+ }
}
-sub ProblemStatisticsLegend {
- my $Ptr = '';
- $Ptr = '
';
- $Ptr .= '
';
- $Ptr .= '#Stdnts
';
- $Ptr .= '
Total Number of Students opened the problem.';
- $Ptr .= '
';
- $Ptr .= 'Tries
';
- $Ptr .= '
Total Number of Tries for solving the problem.';
- $Ptr .= '
';
- $Ptr .= 'Mod
';
- $Ptr .= '
Maximunm Number of Tries for solving the problem.';
- $Ptr .= '
';
- $Ptr .= 'Mean
';
- $Ptr .= '
Average Number of the tries. [ Tries / #Stdnts ]';
- $Ptr .= '
';
- $Ptr .= '#YES
';
- $Ptr .= '
Number of students solved the problem correctly.';
- $Ptr .= '
';
- $Ptr .= '#yes
';
- $Ptr .= '
Number of students solved the problem by override.';
- $Ptr .= '
';
- $Ptr .= '%Wrng
';
- $Ptr .= '
Percentage of students tried to solve the problem ';
- $Ptr .= 'but still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]';
- $Ptr .= '
';
- $Ptr .= 'DoDiff
';
- $Ptr .= '
Degree of Difficulty of the problem. ';
- $Ptr .= '[ 1 - ((#YES+#yes) / Tries) ]';
- $Ptr .= '
';
- $Ptr .= 'S.D.
';
- $Ptr .= '
Standard Deviation of the tries. ';
- $Ptr .= '[ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1) ';
- $Ptr .= 'where Xi denotes every student\'s tries ]';
- $Ptr .= '
';
- $Ptr .= 'Skew.
';
- $Ptr .= '
Skewness of the students tries.';
- $Ptr .= '[(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]';
- $Ptr .= '
';
- $Ptr .= 'Dis.F.
';
- $Ptr .= '
Discrimination Factor: A Standard for evaluating the ';
- $Ptr .= 'problem according to a Criterion ';
- $Ptr .= '[Applied Criterion in %27 Upper Students - ';
- $Ptr .= 'Applied the same Criterion in %27 Lower Students] ';
- $Ptr .= '1st Criterion for Sorting the Students: ';
- $Ptr .= 'Sum of Partial Credit Awarded / Total Number of Tries ';
- $Ptr .= '2nd Criterion for Sorting the Students: ';
- $Ptr .= 'Total number of Correct Answers / Total Number of Tries';
- $Ptr .= '
';
- $Ptr .= '
Disc.
';
- $Ptr .= '
Number of Students had at least one discussion.';
- $Ptr .= '
';
-
- return $Ptr;
-}
-
-#------- Processing upperlist and lowerlist according to each problem
-sub ProcessDiscriminant {
- my ($List,$r) = @_;
- my @sortedList = sort (@$List);
- my $Count = scalar @sortedList;
- my $Problem;
- my @Dis;
- my $Slvd=0;
- my $tmp;
- my $Sum1=0;
- my $Sum2=0;
- my $nIndex=0;
- my $nStudent=0;
- my %Proc=undef;
- while ($nIndex<$Count) {
-# $r->print(" $nIndex) $sortedList[$nIndex]");
- ($Problem,$tmp)=split(/\=/,$sortedList[$nIndex]);
- @Dis=split(/\+/,$tmp);
- my $Temp = $Problem;
- do {
- $nIndex++;
- $nStudent++;
- $Sum1 += $Dis[0];
- $Sum2 += $Dis[1];
- ($Problem,$tmp)=split(/\=/,$sortedList[$nIndex]);
- @Dis=split(/\+/,$tmp);
- } while ( $Problem eq $Temp && $nIndex < $Count );
- $Proc{$Temp}=($Sum1/$nStudent).':'.($Sum2/$nStudent);
-# $r->print(" $nIndex) $Temp --> ($nStudent) $Proc{$Temp}");
- $Sum1=0;
- $Sum2=0;
- $nStudent=0;
- }
-
- return %Proc;
-}
-
-#------- Creating Discimination factor
-sub Discriminant {
- my ($discriminant,$r)=@_;
- my @discriminantKeys=keys(%$discriminant);
- my $Count = scalar @discriminantKeys;
-
- my $UpCnt = int(0.27*$Count);
- my $low=0;
- my $up=$Count-$UpCnt;
- my @UpList=();
- my @LowList=();
-
- $Count=0;
- foreach my $key (sort(@discriminantKeys)) {
- $Count++;
- if($low < $UpCnt || $Count > $up) {
- $low++;
- my $str=$discriminant->{$key};
- foreach(split(/\&/,$str)){
- if($_) {
- if($low<$UpCnt) { push(@LowList,$_); }
- else { push(@UpList,$_); }
+sub sort_data {
+ my ($sortkey) = @_;
+ return if (! @StatsArray);
+ #
+ # Sort the data
+ my $sortby = undef;
+ foreach my $field (@Fields) {
+ if ($sortkey eq $field->{'name'}) {
+ $sortby = $field->{'name'};
+ }
+ }
+ if (! defined($sortby) || $sortby eq '' || $sortby eq 'problem_num') {
+ $sortby = 'container';
+ }
+ if ($sortby ne 'container') {
+ # $sortby is already defined, so we can charge ahead
+ if ($sortby =~ /^(title|part)$/i) {
+ # Alpha comparison
+ @StatsArray = sort {
+ lc($a->{$sortby}) cmp lc($b->{$sortby}) ||
+ lc($a->{'title'}) cmp lc($b->{'title'}) ||
+ lc($a->{'part'}) cmp lc($b->{'part'});
+ } @StatsArray;
+ } else {
+ # Numerical comparison
+ @StatsArray = sort {
+ my $retvalue = 0;
+ if ($b->{$sortby} eq 'nan') {
+ if ($a->{$sortby} ne 'nan') {
+ $retvalue = -1;
+ } else {
+ $retvalue = 0;
+ }
}
- }
+ if ($a->{$sortby} eq 'nan') {
+ if ($b->{$sortby} ne 'nan') {
+ $retvalue = 1;
+ }
+ }
+ if ($retvalue eq '0') {
+ $retvalue = $b->{$sortby} <=> $a->{$sortby} ||
+ lc($a->{'title'}) <=> lc($b->{'title'}) ||
+ lc($a->{'part'}) <=> lc($b->{'part'});
+ }
+ $retvalue;
+ } @StatsArray;
}
}
- my %DisUp = &ProcessDiscriminant(\@UpList,$r);
- my %DisLow = &ProcessDiscriminant(\@LowList,$r);
+ #
+ # Renumber the data set
+ my $count;
+ foreach my $data (@StatsArray) {
+ $data->{'problem_num'} = ++$count;
+ }
+ return;
+}
- return (\%DisUp, \%DisLow);
-}
+########################################################
+########################################################
-#---- END Problem Statistics Web Page ----------------------------------------
+=pod
-#---- Problem Statistics Graph Web Page --------------------------------------
+=item &get_statistics()
-# ------------------------------------------- Prepare data for Graphical chart
+Wrapper routine from the call to loncoursedata::get_problem_statistics.
+Calls lonstathelpers::get_time_limits() to limit the data set by time
+and &compute_discrimination_factor
+
+Inputs: $sequence, $resource, $part, $problem_num
+
+Returns: Hash reference with statistics data from
+loncoursedata::get_problem_statistics.
+
+=cut
+
+########################################################
+########################################################
+sub get_statistics {
+ my ($sequence,$resource,$part,$problem_num) = @_;
+ #
+ my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
+ my $symb = $resource->{'symb'};
+ my $courseid = $ENV{'request.course.id'};
+ #
+ my $data = &Apache::loncoursedata::get_problem_statistics
+ (\@Apache::lonstatistics::SelectedSections,
+ $Apache::lonstatistics::enrollment_status,
+ $symb,$part,$courseid,$starttime,$endtime);
+ $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'});
+ #
+ $data->{'deg_of_disc'} = &compute_discrimination_factor($resource,$part,$sequence);
+ return $data;
+}
-sub BuildGraphicChart {
- my ($ylab,$r,$cacheDB)=@_;
- my %cache;
- my $Col;
- my $data='';
- my $count = 0;
- my $Max = 0;
- unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
- return 'Unable to tie database.';
+###############################################
+###############################################
+
+=pod
+
+=item &compute_discrimination_factor()
+
+Inputs: $Resource, $Sequence
+
+Returns: integer between -1 and 1
+
+=cut
+
+###############################################
+###############################################
+sub compute_discrimination_factor {
+ my ($resource,$part,$sequence) = @_;
+ my @Resources;
+ foreach my $res (@{$sequence->{'contents'}}) {
+ next if ($res->{'symb'} eq $resource->{'symb'});
+ push (@Resources,$res->{'symb'});
+ }
+ #
+ # rank
+ my $ranking =
+ &Apache::loncoursedata::rank_students_by_scores_on_resources
+ (\@Resources,
+ \@Apache::lonstatistics::SelectedSections,
+ $Apache::lonstatistics::enrollment_status,undef);
+ #
+ # compute their percent scores on the problems in the sequence,
+ my $number_to_grab = int(scalar(@{$ranking})/4);
+ my $num_students = scalar(@{$ranking});
+ my @BottomSet = map { $_->[&Apache::loncoursedata::RNK_student()];
+ } @{$ranking}[0..$number_to_grab];
+ my @TopSet =
+ map {
+ $_->[&Apache::loncoursedata::RNK_student()];
+ } @{$ranking}[($num_students-$number_to_grab)..($num_students-1)];
+ my ($bottom_sum,$bottom_max) =
+ &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@BottomSet);
+ my ($top_sum,$top_max) =
+ &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@TopSet);
+ my $deg_of_disc;
+ if ($top_max == 0 || $bottom_max==0) {
+ $deg_of_disc = 'nan';
+ } else {
+ $deg_of_disc = ($top_sum/$top_max) - ($bottom_sum/$bottom_max);
}
-
- my $p_count = $cache{'ProblemCount'};
+ #&Apache::lonnet::logthis(' '.$top_sum.'/'.$top_max.
+ # ' - '.$bottom_sum.'/'.$bottom_max);
+ return $deg_of_disc;
+}
+
+###############################################
+###############################################
+
+=pod
+
+=item ProblemStatisticsLegend
+
+=over 4
+
+=item #Stdnts
+Total number of students attempted the problem.
+
+=item Tries
+Total number of tries for solving the problem.
+
+=item Max Tries
+Largest number of tries for solving the problem by a student.
+
+=item Mean
+Average number of tries. [ Tries / #Stdnts ]
+
+=item #YES
+Number of students solved the problem correctly.
+
+=item #yes
+Number of students solved the problem by override.
+
+=item %Wrong
+Percentage of students who tried to solve the problem
+but is still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]
+
+=item DoDiff
+Degree of Difficulty of the problem.
+[ 1 - ((#YES+#yes) / Tries) ]
+
+=item S.D.
+Standard Deviation of the tries.
+[ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1)
+where Xi denotes every student\'s tries ]
+
+=item Skew.
+Skewness of the students tries.
+[(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]
+
+=item Dis.F.
+Discrimination Factor: A Standard for evaluating the
+problem according to a Criterion
+
+=item [Criterion to group students into %27 Upper Students -
+and %27 Lower Students]
+1st Criterion for Sorting the Students:
+Sum of Partial Credit Awarded / Total Number of Tries
+2nd Criterion for Sorting the Students:
+Total number of Correct Answers / Total Number of Tries
+
+=item Disc.
+Number of Students had at least one discussion.
+
+=back
+
+=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;
- for ( my $k=0; $k<$p_count;$k++) {
- my @Temp=split(/\:/,$cache{'GraphGif:'.$k});
- my $inf = $Temp[$Col];
- if ( $Max < $inf ) {$Max = $inf;}
- $data .= $inf.',';
- $count++;
- }
- untie(%cache);
-# $r->print(" count=$p_count >>data= $data");
-
- if ( $Max > 1 ) {
- $Max += (10 - $Max % 10);
- $Max = int($Max);
- } else { $Max = 1; }
-
- my $cid=$ENV{'request.course.id'};
-
- if ( $ylab eq 'DoDiff Graph' ) {
- $ylab = 'Degree-of-Difficulty';
- $Col = 0;
+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 {
- $ylab = 'Wrong-Percentage';
- $Col = 1;
+ if (exists($hooks{$hookname})) {
+ push(@{$hooks{$hookname}},$subref);
+ } else {
+ $hooks{$hookname} = [$subref];
+ }
}
- my $Course = $ENV{'course.'.$cid.'.description'};
- $Course =~ s/\ /"_"/eg;
- my $GData=$Course.'&'.'Problems#'.'&'.$ylab.'&'.
- $Max.'&'.$count.'&'.$data;
+ return;
+}
- $r->print('');
+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
+
+############################################################
+############################################################
+
1;
__END__