--- loncom/cgi/graph.png	2002/05/13 16:52:11	1.11
+++ loncom/cgi/graph.png	2003/10/09 15:56:41	1.23
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# $Id: graph.png,v 1.11 2002/05/13 16:52:11 minaeibi Exp $
+# $Id: graph.png,v 1.23 2003/10/09 15:56:41 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,72 +25,131 @@
 # http://www.lon-capa.org/
 #
 # The LearningOnline Network with CAPA
-# Behrouz Minaei
-# YEAR=2001
-# 9/13/01, 9/25/01, 10/6/01, 10/9/01, 12/25/01
-# YEAR=2002
-# 2/1/02, 5/13/02, 
+#
 # A CGI script that dynamically outputs a graphical chart for lonstatistics.
 # 
 #### 
 
+=pod
+
+=head1 NAME
+
+graph.png
+
+=head1 SYNOPSIS
+
+produces plots based on input
+
+=head1 DESCRIPTION
+
+graph.png is a cgi-bin script which produces plots based on input data.
+
+The query string is expected to be as follows (without whitespace):
+
+escape(Plot title) & escape(X label)& escape(Y label) & Maximum Y value &
+Number of bars & $data1 & $data2
+
+$data1 and $data2 are expected to be comma seperated lists of numbers.
+escape( value ) means the values must be run through lonnet::escape.
+
+=cut
+
 use strict;
 use GD::Graph::bars;
 use GD::Graph::colour;
 use GD::Graph::Data;
 
+sub unescape {
+    my $str=shift;
+    $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
+    return $str;
+}
+
 $|=1;   # Autoflush after each print/write
-my ($Titr,$xlab,$ylab,$Max,$PNo,$data1,$data2)=split(/&/,$ENV{'QUERY_STRING'});
+my ($Titr,$xlab,$ylab,$Max,$NumBars,$data1,$data2)=split(/&/,$ENV{'QUERY_STRING'});
+$Titr = &unescape($Titr);
+$xlab = &unescape($xlab);
+$ylab = &unescape($ylab);
 
 my @data11=split(/\,/,$data1);
 my @data12=split(/\,/,$data2);
+my $skip_x = 1;
+#my $bar_space=1;
+my $bar_width=10;
 
 my @xlabels;
-for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
+
+for (my $nIdx=0; $nIdx<$NumBars; $nIdx++ ) {
     $xlabels[$nIdx]=$nIdx+1;
-} 
+}
 
-#my $bg = (defined(@data2)) ? 'lorange' : 'white';
+#if ($Titr =~ /^Percentage$/){
+#    for (my $nIdx=0; $nIdx<$NumBars; $nIdx++ ) {
+#        $xlabels[$nIdx]=$nIdx;
+#    }
+#    @data11=();
+#    @data11=split(/\,/,$data2);
+#    @data12=();
+#    $Titr = '';
+#} else {
+#} 
 
 my @data =(\@xlabels,\@data11,\@data12);
 
-my $Range;
-if ($xlab=~/^Concepts$/){
-    $Range=500;
-} 
-else {
-    if ( $PNo > 10 ) {$Range = 30*$PNo;}
-    else { $Range = 400+30*$PNo; }
+my $width;
+my $height = 200;
+
+if ($NumBars < 10) {
+    $width = 120+$NumBars*15;
+    $skip_x = 1;
+    $bar_width = 15;
+} elsif ($NumBars <= 25) {
+    $width = 120+$NumBars*11;
+    $skip_x = 5;
+    $bar_width = 8;
+} elsif ($NumBars <= 50) {
+    $width = 120+$NumBars*8;
+    $skip_x = 5;
+    $bar_width = 4;
+} else {
+    $width = 120+$NumBars*8;
+    $skip_x = 5;
+    $bar_width = 4;
 }
 
+my $x_tick_offset = 0;
+if ($skip_x > 1) {
+    $x_tick_offset = $skip_x - 1;
+}
 
-my $MyGraph = GD::Graph::bars->new($Range, 400);
+my $MyGraph = GD::Graph::bars->new($width,$height);
 
 $MyGraph->set( 
     x_label         => $xlab,
     y_label         => $ylab,
+    x_label_position => 0.5,
     long_ticks      => 1,
     tick_length     => 0,
     x_ticks         => 0,
-#    title           => 'LON-CAPA Option Response Problem:'.$cid,
     title           => $Titr,
     y_max_value     => $Max,
 #    y_tick_number   => $ytic,
-    y_label_skip    => 1,   
-
-    dclrs           => [ qw( green dgreen lyellow lpurple cyan lorange)],
-    
-    bar_spacing     => 10,
+#    y_label_skip    => 5,
+    x_label_skip    => $skip_x,   
+    x_tick_offset   => $x_tick_offset,
+
+    dclrs           => [ qw( lgreen dgreen lyellow lpurple cyan lorange)],
+    bar_width       => $bar_width,
+#    bar_spacing     => $bar_space,
     cumulate        => 2,
     zero_axis        => 1,
 
 #    legend_placement    => 'RT',
 
     fgclr               => 'black',
-    boxclr              => 'lorange',
+    boxclr              => 'white',
     accentclr           => 'dblue',
     valuesclr           => '#ffff77',
-
     l_margin            => 10,
     b_margin            => 10,
     r_margin            => 10,
@@ -98,19 +157,19 @@ $MyGraph->set(
 
     transparent     => 0,
 ) or warn $MyGraph->error; 
-if ($xlab=~/^Concepts$/){
-    $MyGraph->set_legend( 'Correct Answers', 'Incorrect Answers');
-}
-# Tell the server we are sending a gif graphic
+
+
+# Tell the server we are sending a png graphic
 print <<END;
-Content-type: image/gif
+Content-type: image/png
 
 END
 
 my $BinaryData=$MyGraph->plot(\@data)->png;
 undef $MyGraph;
 binmode(STDOUT);
-open IMG,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into a gif image
-print IMG $BinaryData; # output image
-$|=1; # be sure to flush before closing
-close IMG;
+#open IMG,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into a gif image
+#print IMG $BinaryData; # output image
+#$|=1; # be sure to flush before closing
+#close IMG;
+print $BinaryData;