Next-Generation Sequence Assembly: Four Stages of Data Processing and Computational Challenges
Figure 8
(A) Set of contigs with their length. (B) Contigs are sorted in descending order. (C) Lengths of all contigs are added (20+15+10+5+2 = 52 kb) and divided by 2 (52/2 = 26 kb). (D) Lengths are added again until the sum exceeds 26 kb, and hence exceeds 50% of the total length of all contigs: 20+15 = 35 kb≥26; then, N50 is the last added contig, which is 15 kb.