ok($img1, "drawing line chart");
$img1->write(file=>'testout/t30_points.ppm') or die "Can't save img1: ".$img1->errstr."\n";
-cmpimg($img1, 'testimg/t30_points.ppm', 1);
+cmpimg($img1, 'testimg/t30_points.ppm', 40_000);
unless (is(@warned, 0, "should be no warnings")) {
diag($_) for @warned;