--- loncom/cgi/graph.png	2002/05/19 15:47:25	1.13
+++ loncom/cgi/graph.png	2003/10/08 15:44:49	1.22
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# $Id: graph.png,v 1.13 2002/05/19 15:47:25 minaeibi Exp $
+# $Id: graph.png,v 1.22 2003/10/08 15:44:49 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,68 +25,112 @@
 # 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/, 5/13, 5/15
+#
 # 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(/&/,$ENV{'QUERY_STRING'});
+$Titr = &unescape($Titr);
+$xlab = &unescape($xlab);
+$ylab = &unescape($ylab);
 
 my @data11=split(/\,/,$data1);
 my @data12=split(/\,/,$data2);
+my $skip_x = 1;
+my $bar_space=10;
 
 my @xlabels;
-for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
-    $xlabels[$nIdx]=$nIdx+1;
-} 
-
 
+if ($Titr =~ /^Percentage$/){
+    for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
+        $xlabels[$nIdx]=$nIdx;
+    }
+    @data11=();
+    @data11=split(/\,/,$data2);
+    @data12=();
+    $Titr = '';
+} else {
+     for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
+         $xlabels[$nIdx]=$nIdx+1;
+     }
+} 
 
 my @data =(\@xlabels,\@data11,\@data12);
 
-my $Range1;
-my $Range2;
+my $width;
+my $height = 200;
 
 if ($xlab=~/^Concepts$/){
-    $Range1=270;
-    $Range2=200;
+    $width=270;
+} elsif ($xlab=~/^Problem\snumber$/){
+    $width=450;
 } else {
-    if ( $PNo > 10 ) {
-	$Range1 = 20*$PNo;
-    } else { 
-        $Range1 = 250+30*$PNo; 
-    }
-    $Range2=200; 
+    $width=($PNo==100) ? 800 : (120+$PNo*10); 
+    $skip_x=5;
+    $bar_space=1;
 }
 
+my $x_tick_offset = 0;
+if ($skip_x > 1) {
+    $x_tick_offset = $skip_x - 1;
+}
 
-my $MyGraph = GD::Graph::bars->new($Range1,$Range2);
+my $MyGraph = GD::Graph::bars->new($width,$height);
 
 $MyGraph->set( 
- #   x_label         => $xlab,
+    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,   
+    y_label_skip    => 5,
+    x_label_skip    => $skip_x,   
+    x_tick_offset   => $x_tick_offset,
 
     dclrs           => [ qw( lgreen dgreen lyellow lpurple cyan lorange)],
     
-    bar_spacing     => 10,
+    bar_spacing     => $bar_space,
     cumulate        => 2,
     zero_axis        => 1,
 
@@ -103,30 +147,19 @@ $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
 
-#$MyGraph->set_y_label_font('/home/httpd/cgi-bin/cetus.ttf', 16);
-#$MyGraph->set_x_label_font('/home/httpd/cgi-bin/cetus.ttf', 16);
-#$MyGraph->set_y_axis_font('/home/httpd/cgi-bin/cetus.ttf', 12);
-#$MyGraph->set_x_axis_font('/home/httpd/cgi-bin/cetus.ttf', 12);
-#$MyGraph->set_title_font('/home/httpd/cgi-bin/cetus.ttf', 18);
-#$MyGraph->set_legend_font('/home/httpd/cgi-bin/cetus.ttf', 10);
-#$MyGraph->set_values_font('/home/httpd/cgi-bin/cetus.ttf', 10);
-
-
 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;