$mygraph->set(
    x_label     => 'Log_Date',
    y_label     => $y_label,
    x_label_skip => 30,
    x_labels_vertical => true,
    title       => $title,
    legend_placement => 'BL',
    legend_marker_height => 12,
    dclrs => [ qw(green blue red yellow brown orange) ],
) or warn $mygraph->error;
$mygraph->set_legend(@legend_keys);
$mygraph->set_title_font('/fonts/arial.tf', 24);
my $myimage = $mygraph->plot(\@data) or die $mygraph->error;