use PNGgraph::linespoints;

print STDERR "Processing sample 4-2\n";

@data =  read_data_from_csv("sample42.dat")
    or die "Cannot read data from sample42.dat";

$my_graph = new PNGgraph::linespoints( );

$my_graph->set(
    x_label => 'X Label',
    y_label => 'Y label',
    title => 'A Lines and Points Graph, reading a CSV file',
    y_max_value => 80,
    y_tick_number => 6,
    y_label_skip => 2,
    markers => [ 1, 5 ],
);

$my_graph->set_legend( 'data set 1', 'data set 2' );

$my_graph->plot_to_png( "sample42.png", \@data );

exit;

sub read_data_from_csv
{
    my $fn = shift;
    my @d = ();

    open(ZZZ, $fn) || return ();

    while (<ZZZ>)
    {
        chomp;
        # you might want Text::CSV here
        my @row = split /,/;

        for (my $i = 0; $i <= $#row; $i++)
        {
            undef $row[$i] if ($row[$i] eq 'undef');
            push @{$d[$i]}, $row[$i];
        }
    }

    close (ZZZ);

    return @d;
}

