in reply to Re^2: GD::GRAPH:linespoints problem
in thread GD::GRAPH:linespoints problem

use strict;
use warnings;
use GD::Graph::linespoints;
my $i = 0;
while (<>) {
  my $g = GD::Graph::linespoints->new(100,100);

  $g->set( 
      x_label           => 'X Label',
      y_label           => 'Y label',
      title             => 'Some simple graph',
      y_max_value       => 8,
      y_tick_number     => 8,
      y_label_skip      => 2
  ) or die $g->error;
  my @line = split / /;
  open F,">plot$i.png" or die $!;
  binmode F;
  my $img =  $g->plot(
       [[ 1, 2, 3, 4],
       \@line]
      ) or die $g->error;
  print F $img->png;
  $i++
}

[download]
Not that it makes any difference; as I suggested before the bug is in YOUR code, not in whatever I make up.
"What should it profit a man, if he should win a flame war, yet lose his cool?"

Replies are listed 'Best First'.
Re^4: GD::GRAPH:linespoints problem
by v_d_g (Initiate) on Mar 03, 2007 at 09:03 UTC
    okay, perhaps you can help me identify the bug using the following file: 
    Start 

comments

1 2
3 4
5 6
7 8

quotes

End 

Start 

comments

8 7
6 5
4 3
2 1 

quotes

End

    [download]
    and the following code (excuse the poor quality) 

    use GD::Graph::linespoints;

my $data_file = "retestfileIN.txt";
open DATA, "$data_file" or die "can't open $data_file $!";
 undef $/;
 $_ = <DATA>;
  close DATA;
$/ = "\n"; 

for my $r (0 .. 1) {
if (/comments(.*?)quotes/sg) { 
    my $tempvar = $1;
    $tempvar=~ s/^\s+|\s+$//g; 
    
    @alltemp = split(/\n/,$tempvar);

    foreach my $line (@alltemp) {
    $line =~ /(\d)\s(.*)/g;
    push(@first, $1);
    push(@second, $2);
    push (@data, ([@first, @second]));
}
}


my $g = GD::Graph::linespoints->new(500,300);  # graph code
  
  $g->set( 
      x_label           => 'X Label',
      y_label           => 'Y label',
      title             => 'Some simple graph',
      y_max_value       => 10,
      y_tick_number     => 8,
      y_label_skip      => 2
  ) or die $g->error;
 
  my $format = $g->export_format;
  open (IMG, ">squot$r.$format") or die $!;
  binmode IMG;
 
  print IMG $g->plot(\@data)->$format();  # end graph code

}

    [download]
    If I include the code for the graph, the IF never makes it to the second set of data (8 7, 6 5, 4 3, 2 1)

    there's my problem

[reply]
[d/l]
[select]
      I think the reason that the graph is not quite right is that you are appending to @data on each pass through the loop, but you don't reinitialize it, so on the second pass @data has both sets of data in it. I assume that GD is ignoring the extra set.

      I would suggest that you do all of the following as a matter of course:

      (1) use warnings;

      (2) use strict;

      (3) add "my" where needed to declare variables in the correct scope (you won't need to explicitly reinitialize @data if it is made local to the loop), and finally

      (4) run the script "perltidy" from the CPAN module Perl::Tidy on your code to fix the indentation. This isn't just esthetic, it can make flaws in scoping and nesting a lot more obvious. (Update: a better description of using command-line perltidy is at http://perltidy.sourceforge.net/.)

[reply]

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