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

I've been fiddling with GD::Graph and GD::Text all day, but this is eluding me.

GD::Graph is easy enough to use, and I have it producing the graphs I want. But now I would like to add a small table of text at the bottom of the returned PNG graphic, and I can't quite figure that out.

I've tried using the instantiated object as the target of a GD::Text::Wrap operation, but it returns the error "Not a GD::Image object". Puzzling, because the docs clearly say: 
$graph->plot(\@data) 
    Plot the chart, and return the GD::Image object.

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So I did this (most of this code is samples from the man pages, I will be using this with real data once I get the output done properly): 
#!/usr/bin/perl

use GD::Graph::bars3d;
use GD::Text::Wrap;
        my @data = (
           [qw (Sun Mon Tue Wed Thu Fri Sat) ],
           [ 1100, 1500,  1800,  1950,  2324,  2162,  140],
           [ 103, 2000,  1173,  908,  232,  1200,  100],
        );

my $graph = new GD::Graph::bars3d( 495, 211 );
        $graph->set(
                x_label           => 'Day of the week',
                dclrs             => [ qw(red dgreen) ],
                bar_spacing       => 10,
                cumulate          => 1,
        );
        my ($gd) =  $graph->plot( \@data )->png;
my $text = <<EOSTR;
Lorem ipsum dolor sit amet, consectetuer adipiscing elit,
sed diam nonummy nibh euismod tincidunt ut laoreet dolore
magna aliquam erat volutpat.
EOSTR


  my $wrapbox = GD::Text::Wrap->new( $gd,
      line_space  => 4,
      color       => 'black',
      text        => $text,
  );

binmode STDOUT;
print $gd;

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..Which returns the error:
Not a GD::Image object at ./graphtest.pl line 26

Any clues? I think I just don't know GD well enough to know the best way to do this. All help appreciated.
"Non sequitur. Your facts are un-coordinated." - Nomad

Replies are listed 'Best First'.
Re: Adding text to a GD::Graph object...
by dree (Monsignor) on Jun 22, 2002 at 09:56 UTC
    GD::Text::Wrap require a GD object.
    So you have to put the 3d graph in an image and then make a GD object with it to pass to GD::Text::Wrap.

    This works for me: 
    use GD;
use GD::Graph::bars3d;
use GD::Text::Wrap;
use strict;
my @data = ( 
    ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
    [ 1203,  3500,  3973,  2859,  3012,  3423,  1230]
);
my $graph = GD::Graph::bars3d->new( 400, 300 );
$graph->set( 
    x_label           => 'Day of the week',
        y_label           => 'Number of hits',
        title             => 'Daily Summary of Web Site',
);

my $gd = $graph->plot( \@data );

my $img_tmp="img_tmp.png";
open FILE, ">$img_tmp";
binmode FILE;
print FILE $gd->png;
close FILE;

my $gd_image = GD::Image->newFromPng($img_tmp) ;

my $text = <<EOSTR;
Lorem ipsum dolor sit amet, consectetuer adipiscing elit,
sed diam nonummy nibh euismod tincidunt ut laoreet dolore
magna aliquam erat volutpat.
EOSTR

my $wrapbox = GD::Text::Wrap->new( $gd_image,
        line_space  => 4,
        color       => 'black',
        text        => $text,
);

$wrapbox->set(align => 'left', width => 120);
$wrapbox->draw(110,140);

open FILE, ">img.png";
binmode FILE;
print FILE $gd_image->png;
close FILE;

    [download]

    In my Win32 box, it works properly with GD 1.27.2.
    If you have a more recent version of GD, instead making a temporary image, you could use: 
    my $gd_image = GD::Image->newFromPngData($gd->png);

    [download]
[reply]
[d/l]
[select]
      Thanks!

      THere's just one problem: It doesn't work for me. :-(

      Any suggestions? Maybe I've got a bad library somewhere?

      > ./graphtest.pl 
Not a GD::Image object at ./graphtest.pl line 26
> perl -mGD -e 'print "$GD::VERSION\n"'
1.33
> perl -v 
This is perl, version 5.005_03 built for i386-linux

      [download]
      "Non sequitur. Your facts are un-coordinated." - Nomad
[reply]
[d/l]
Re: Adding text to a GD::Graph object...
by Clownburner (Monk) on Jun 22, 2002 at 01:22 UTC
    Ooh, minor bug: If this wasn't returning an error, I'd probably want to be printing $wrapbox instead of $gd. So sue me. ;-)
    "Non sequitur. Your facts are un-coordinated." - Nomad
[reply]

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