in reply to Re: Re: Drawing graphs with perl
in thread Drawing graphs with perl

I usually work better when I have code in front of me to poke holes at.... so I'll provide some. This is taken straight from the CPAN download's examples for DBD::Chart here is some sample code for a pie chart: 

#!/usr/bin/perl -w
use DBI;
use DBD::Chart;
 
open(OUTF, ">pietest.html");
print OUTF "<html><body>
<img src=simppie.png>
<img src=updpie.png>
<img src=delpie.png>
</body></html>\n";
close OUTF;
 
$dbh = DBI->connect('dbi:Chart:');
#
#       simple piechart
#
$dbh->do('CREATE TABLE pie (region CHAR(20), sales FLOAT)');
$sth = $dbh->prepare('INSERT INTO pie VALUES( ?, ?)');
$sth->execute('East', 2756.34);
$sth->execute('Southeast', 3456.78);
$sth->execute('Midwest', 1234.56);
$sth->execute('Southwest', 4569.78);
$sth->execute('Northwest', 33456.78);
 
$rsth = $dbh->prepare(
"SELECT PIECHART FROM pie
        WHERE WIDTH=400 AND HEIGHT=400 AND
        TITLE = \'Sales By Region\' AND
        COLOR=(red, green, blue, lyellow, lpurple) AND
        SIGNATURE=\'Copyright(C) 2001, GOWI Systems, Inc.\'
        AND     BACKGROUND=lgray");
$rsth->execute;
$rsth->bind_col(1, \$buf);
$rsth->fetch;
open(OUTF, '>simppie.png');
binmode OUTF;
print OUTF $buf;
close(OUTF);
print "simppie.png OK\n";
 
$updsth = $dbh->prepare('UPDATE pie SET sales = ? WHERE region = \'Nor
+thwest\' ');
$updsth->bind_param(1, 12999.45);
$updsth->execute;
 
$rsth->execute;
$rsth->bind_col(1, \$buf);
$rsth->fetch;
open(OUTF, '>updpie.png');
binmode OUTF;
print OUTF $buf;
close(OUTF);
print "updpie.png OK\n";
 
$delsth = $dbh->prepare('delete from pie where region = ? ');
$delsth->bind_param(1, 'Northwest');
$delsth->execute;
 
$rsth->execute;
$rsth->bind_col(1, \$buf);
$rsth->fetch;
open(OUTF, '>delpie.png');
binmode OUTF;
print OUTF $buf;
close(OUTF);
print "delpie.png OK\n";

[download]

I ran the code and did an "ls" in my CWD and lo and behold I found: 

[pberghol@cowdawg pietest]$ ls
delpie.png  pietest.html  pietest.pl  simppie.png  updpie.png

[download]

I bet if I open pietest.html I should see a pretty chart. I tried it and I did. If you look here you'll see what I mean.

In Section Seekers of Perl Wisdom