rakheek has asked for the wisdom of the Perl Monks concerning the following question:

Hi Friends, I have a code where I am doing DBI query and plotting data using perl GD module. My code does not give any error but also does not plot the data. I have tried sample data and it seems to work. Any clues? The code is as below: 
use CGI qw(:standard);
use DBI;
use GD::Graph::bars;
use GD::Graph::Data;

$cgi= new CGI;

#print $cgi->header( -type => 'image/png');
print $cgi->header ;

#print $cgi->start_html(-title=>'Basic CGI');

#print $cgi->table({border=>1});


#$project_name = $input('Project');

if ($input{'Project'} eq "DEIMOS") {

#my $run_id_number="499";
my $dbh = DBI->connect('dbi:mysql:bugz:bugzilla.telegent.com:3306', 's
+wqa', 'sImANten') or die "Connection Error: $DBI::errstr\n";
my $sql = "Select log_date, open_cnt from swqa.Poseidon where product 
+like '%DEIMOS%' and rec_type='1'" and log_date >= '2010-01-01';
my $sth = $dbh->prepare($sql);
$sth->execute or die "SQL Error: $DBI::errstr\n";
# HTML TABLE

#print '<title> QA Metric charts for DEIMOS</title>';
#print '<tr><td><b>Open P1-P2 Bugs</b></td></tr>';
#
my @log_date = ();
my @deimos_open_bugs = ();
while (my @row = $sth->fetchrow_array) {
#       print "<tr><td>$row[0]</tr></td>\n";
        push @log_date, $row[0];
        push @deimos_open_bugs, $row[1];
        }
$dbh->disconnect;

my $mygraph = GD::Graph::bars->new();
$mygraph->set(
    x_label     => 'Log_Date',
    y_label     => 'Open P1-P2 Bugs',
    title       => 'DEIMOS Data',
);
#my @data = (['Fall 01', 'Spr 01', 'Fall 02', 'Spr 02' ],
#            [80, 90, 85, 75],
#            [76, 55, 75, 95],
#            [66, 58, 92, 83]);

#print $cgi->end_table;
#print 'Content-Type: image/png\n\n';
my $data = GD::Graph::Data->new([$log_date], [$deimos_open_bugs]) or d
+ie GD::Graph::Data->error;
my $myimage = $mygraph->plot(\@data) or die $mygraph->error;


binmode STDOUT;
print $myimage->png;

[download]

Replies are listed 'Best First'.
Re: Having problem graphing with Perl GD module
by BrowserUk (Patriarch) on Mar 12, 2010 at 23:25 UTC

    If you added use strict & use warnings to your code, you'd find about a dozen reasons why what you've posted doesn't work.

    These include

    1. An unclosed if statement.
    2. Assigning to $data and passing \@data.
    3. Where does GD::Graph::Data come from? I can't find it on CPAN (and it surely isn't needed for what you are doing).

    If you cleaned up the obvious things in your code, you'd get a lot closer to being able to solve your own problem.

    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
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      Thank you BrowserUk. Actually, #2 was the problem. I got around with following code. Also, I got rid of GD::Graph::Data. My if is closed. BTW, I am new to perlmonks and am very happy to see quick response on the site. 
      my @data = (\@log_date, \@deimos_open_bugs);
my $myimage = $mygraph->plot(\@data) or die $mygraph->error;

      [download]
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        Oh dear. New maintainer, new fluff. At least it's optional.

        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

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