Comparison of Homopolymer Spectrum and k -mer Spectrum in SRR000868 (a), SRR000870 (b) and SRR639330 (c) datasets, respectively. A homopolymer spectrum is different from a k-mer spectrum, i.e. the multiplicity along the x-axis represents a range of actual sequence length. The comparison between the homopolymer spectrum and k-mer spectrum of SRR000868, SRR000870 and SRR639330 datasets are shown in a, b and c, respectively. The cut-off values chosen for the SRR000868, SRR000870 and SRR639330 datasets are 3, 3 and 6, respectively.