Quick graphs with Perl / GD::Graph

So I had to quickly whip up some graphs today at work based on values coming in from one of our database tables. Nothing better then Perl and GD (GD::Graph) for a quick and effective solution.

use strict; use DBI; use GD::Graph::bars; use GD::Graph::Data;

my $db_host = ‘‘XXXXXX’’; my $db_name = ‘‘XXXXXX’’;
my $db_user = ‘‘XXXXXX’’; my $db_pass = ‘‘XXXXXX’’; my $query = “select month, undelivered from XXXXX where XXXXX”;

create labels and values for x-axis

my ($labels, $values) = get_data_from_sql($db_host, $db_name, $db_user, $db_pass, $query);

graph and save the output

graph($labels, $values, “Month”, “Undelivered”, “Undelivered Messages by Month”, “undelivered.png”);

sub get_data_from_sql($) { my ($db_host, $db_name, $db_user, $db_pass, $query) = @_;

my $dbh = DBI->connect(“dbi:mysql:$db_name:$db_host”, $db_user, $db_pass) or die “Couldn’‘t connect to database: “ . DBI->errstr;

my $sth = $dbh->prepare($query) or die “Couldn’‘t prepare statement: “ . $dbh->errstr;

$sth->execute(); my @row= undef;

my @labels = (); my @values = ();

while (@row = $sth->fetchrow_array()) { push @labels, $row[0]; push @values, $row[1]; }


return (\@labels, \@values); }

sub graph($$) { my ($labels, $values, $x_label, $y_label, $title, $out_file) = @_;

my $data = GD::Graph::Data->new([$labels, $values,]) or die GD::Graph::Data->error;

my $my_graph = GD::Graph::bars->new();

$my_graph->set( x_label => $x_label, y_label => $y_label, title => $title, bar_spacing => 8, shadow_depth => 4, shadowclr => ‘‘dred’’, transparent => 0, ) or warn $my_graph->error;

$my_graph->plot($data) or die $my_graph->error; my $gd = $my_graph->plot($data) or die $my_graph->error; open(IMG, “>$out_file”) or die $!; binmode IMG; print IMG $gd->png; }

If you do not want your data coming from an SQL statement simply fill in $labels and $values with anything you want, like:

$labels = ['’Monday’’, ‘‘Tuesday’’, ‘‘Wednesday’’]; $data = [45, 66, 89];

Pretty straight forward and handy. the graph looks like this.

Written on July 8, 2009