Discrimination between W and non-W contigs based on read depth and coverage for each contig. Known W contigs are shown in red, known Z or autosomal contigs are in blue, and unmapped contigs are in gray. Note that the W contigs (red dots) exhibit very low alignment and read depth to male-derived sequences. The W contigs form a distinct cluster from the autosomal or Z contigs. The goal is to classify all the unmapped contigs (gray dots) into one of two classes: W or non-W.