Figure 3. Alignment and annotation statistics. Quality control statistics.

(a) Fraction of pairs passing all filters (CAGEscan pairs) or discarded at key steps of the processing pipeline (see Fig. 2). The central block of stack bars represents each library individually. The left block aggregates them by sequencing batch, named by the sequencing run identifier. The right block aggregates the libraries by sample type. Each sample type is represented by one colour, that is also used to colour the library identifiers and the sequence identifiers in the other blocks. Batches comprising multiple types are indicated by multiple colours. (b) Fraction of pairs starting in a Promoter, Exon, or Other (non-promoter, non-exon) region.