DBD::Chart::Plot ??

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

Dear Monks, I want to plot a simple graph and have decided to use DBD::Chart::Graph mainly because of the number of colours available and because you can plot scatter graphs.

I have basically copied code from the cpan web-site for this module but I can't get it to work but I don't get errors either. Can anyone spot the problem? Thanks!

#!/biol/programs/perl580/bin/perl

use DBD::Chart::Plot;

my $img = DBD::Chart::Plot->new();
my @k = ('1','1','3','5');
my @h = ('0.1','0.5','0.4','0.9');
$img->setPoints(\@k, \@h, 'blue line nopoints');
    $img->setOptions (
        title => 'My Graph Title',
        xAxisLabel => 'my X label',
        yAxisLabel => 'my Y label' );
    print $img->plot;

    open (WR,'>plot3.png') or die ("Failed to write file: $!");
    binmode WR;            # for DOSish platforms
    print WR $img->plot();
    close WR;
[download]

Formatting repaired by davido

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Re: DBD::Chart::Plot ?? by itub (Priest) on Jan 24, 2005 at 16:52 UTC
The problem is that you have to specify the file format when you call the plot method. That is, replace `print $img->plot;` [download] with `print $img->plot('png');` [download] Yes, the documentation is wrong, and the module should complain or have a default if no format is provided. Added: The format you provide has to be the name of one of the "Image Data Output Methods", as listed in the GD documentation.	[reply] [d/l] [select]
Re^2: DBD::Chart::Plot ?? by Anonymous Monk on Jan 24, 2005 at 17:57 UTC
Thanks a million itub ! - now it works	[reply]
Re: DBD::Chart::Plot ?? by CountZero (Bishop) on Jan 24, 2005 at 15:27 UTC
Did you check the return value of the `setpoints` function? As per the docs it returns a positive integer upon success and an undef on failure. Update I tried your code and it doesn't work for me either. The problem is with the `plot` function which doesn't return anything. CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law	[reply] [d/l] [select]
Re: DBD::Chart::Plot ?? by holli (Abbot) on Jan 24, 2005 at 15:21 UTC
Are you sure you have all rerequisites installed? These are, according to the docs of DBD::Chart: Perl 5.6.0 minimum DBI 1.14 minimum DBD::Chart::Plot 0.80 (included with this package) GD X.XX minimum GD::Text X.XX minimum Time::HiRes libpng zlib libgd jpeg-6b holli, regexed monk	[reply]