#!/usr/bin/perl # # $Id: graph.png,v 1.35 2005/05/25 22:31:51 albertel Exp $ # # Copyright Michigan State University Board of Trustees # # This file is part of the LearningOnline Network with CAPA (LON-CAPA). # # LON-CAPA is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # LON-CAPA is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with LON-CAPA; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # /home/httpd/cgi-bin/graph.gif # # http://www.lon-capa.org/ # # The LearningOnline Network with CAPA # # A CGI script that dynamically outputs a graphical chart for lonstatistics. # #### =pod =head1 NAME graph.png =head1 SYNOPSIS produces plots from data stored in users environment. =head1 DESCRIPTION graph.png is a cgi-bin script which produces plots based on data stored in the users environment. The users cookie is checked prior to producing a plot. The query string is expected to be an identifier, $id. The parameters defining the plot must be stored in the environment as $ENV{'cgi.'.$id.'.'.$dataname}. Two types of plots can be produced, 'bar' and 'xy'. The 'xy' graph can will 1 or 2 y-axes if the parameter 'two_axes' is set to false or true respectively. See perldoc GD::Graph and loncommon::DrawBarGraph, loncommon::DrawXYGraph, and loncommon::DrawXYYGraph. =cut use strict; use lib '/home/httpd/lib/perl'; use GD::Graph::bars; use GD::Graph::lines; use GD::Graph::colour; use GD::Graph::Data; use LONCAPA::loncgi; sub unescape { my $str=shift; $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg; return $str; } sub error { my ($error) = @_; my $Str = <<"END"; Content-type: text/html
There was an error producing the graph you requested.
$error
END return $Str; } my $id = $ENV{'QUERY_STRING'}; # # usage: &get_env($name,$default) sub get_env { my $key = 'cgi.'.$id.'.'.(shift()); return shift if (! exists($Apache::lonnet::env{$key})); return $Apache::lonnet::env{$key}; } if (! &LONCAPA::loncgi::check_cookie_and_load_env()) { print <