my $len = 1 + max map { length } @lines; # left padding
my $size = ($width - $lenval - $len) / $order[0]; # bar multiplication
+sub orderpos { ($order[$_[0]] + $order[$_[0] + .5]) / 2 * $size }
my @barmark;
-my $mean = ($order[$#order / 2] + $order[$#order / 2 + .5]) / 2;
-$barmark[ $mean * $size ] = '+'; # mean
+$barmark[ orderpos($#order / 2) ] = '+'; # mean
for my $nr (0 .. $#lines) {
my $val = $values[$nr];