def main(reads_file, ref_file, dir, error_rate):
sys.stderr.write("Reading reference" + "\n")
ref = sorted(list(SeqIO.parse_fasta(open(ref_file, "r"))),
key=lambda rec: len(rec))[-1]
ref = Contig(ref.seq, ref.id)
refs = ContigCollection()
for i in range(0, len(ref) - 500, 500):
if random.random() > 0.95:
tmp = list(ref.segment(i, i + 500).Seq())
for j in range(error_rate * 500 / 100):
pos = random.randint(0, 499)
tmp[pos] = basic.rc[tmp[pos]]
refs.add(
Contig("".join(tmp),
ref.id + "(" + str(i) + "," + str(i + 500) + ")"))
refs.print_names(sys.stderr)
sys.stderr.write("Reading reads" + "\n")
reads = ReadCollection()
reads.loadFromFasta(open(reads_file, "r"))
sys.stderr.write("Aligning reads" + "\n")
basic.ensure_dir_existance(dir)
aligner = Aligner(DirDistributor(dir))
aligner.alignReadCollection(reads, refs)
sys.stderr.write("Analysing alignments" + "\n")
alignments = []
for read in reads:
alignments.extend(read.alignments)
alignments = filter(lambda al: len(al) > 450, alignments)
alignments = sorted(alignments,
key=lambda al:
(al.seg_to.contig.id, al.seg_from.contig.id))
scorer = Scorer()
scorer.scores.homo_score = 3
scorer.scores.ins_score = 5
scorer.scores.del_score = 5
cnt = 0
for contig, iter in itertools.groupby(alignments,
key=lambda al: al.seg_to.contig):
iter = list(iter)
sys.stderr.write(str(contig) + " " + str(len(iter)) + "\n")
if len(iter) < 150:
for al in iter:
print scorer.accurateScore(al.matchingSequence(),
params.alignment_correction_radius)
cnt += 1
if cnt >= 5000:
break
if cnt >= 5000:
break
def CreateContigCollection(graph_file, contigs_file, min_cov, aligner, polisher, reads, force_unique, all_unique):
sys.stdout.info("Creating contig collection")
if force_unique is None and not all_unique:
graph = SimpleGraph().ReadDot(graph_file)
graph.FillSeq(contigs_file)
covs = []
for e in graph.e.values():
covs.append((e.len, e.cov))
tmp_cov = []
total = sum(l for c,l in covs) / 2
for l, c in sorted(covs)[::-1]:
if total < 0:
break
tmp_cov.append((l, c))
total -= l
avg_cov = float(sum([l * c for l, c in tmp_cov])) / sum(l for l, c in tmp_cov)
sys.stdout.info("Average coverage determined:", avg_cov)
nonunique = set()
for edge in graph.e.values():
if edge.unique and edge.len < 20000 and len(graph.v[edge.start].out) > 1:
if edge.cov >= min_cov and (edge.cov < 0.8 * avg_cov or edge.len > 40000):
alter = ContigStorage()
for e in graph.v[edge.start].out:
if e != edge:
alter.add(Contig(e.seq, e.id))
for al in aligner.localAlign([Contig(edge.seq, edge.id)], alter):#type: AlignmentPiece
if al.percentIdentity() > 0.98 and (al.seg_from.left < 100 and al.seg_to.left < 100 and len(al) > min(500, edge.len)):
nonunique.add(edge.id)
nonunique.add(basic.Reverse(edge.id))
contigs = ContigCollection()
for edge in graph.e.values():
if basic.isCanonocal(edge.id):
if edge.unique and (edge.len > params.min_isolated_length or len(graph.v[edge.end].out) > 0 or len(graph.v[edge.start].inc) > 0):
if edge.cov >= min_cov and (edge.cov < 1.5 * avg_cov or edge.len > 40000):
if edge.id in nonunique:
sys.stdout.info("Edge removed based on alignment to alternative:", edge.id, edge.cov, edge.len)
else:
contigs.add(Contig(edge.seq, edge.id))
else:
sys.stdout.info("Edge removed based on coverage:", edge.id, edge.cov, edge.len)
elif (edge.len > 100000 and edge.cov < 1.5 * avg_cov) or (edge.len > 40000 and 1.3 * avg_cov > edge.cov > 0.7 * avg_cov):
contigs.add(Contig(edge.seq, edge.id))
sys.stdout.info("Edge added based on length and coverage:", edge.id, edge.cov, edge.len)
elif force_unique is not None:
sys.stdout.info("Using forced unique edge set")
sys.stdout.trace(force_unique)
contigs = ContigCollection().loadFromFile(contigs_file).filter(lambda contig: contig.id in force_unique)
else:
sys.stdout.info("Considering all contigs unique")
contigs = ContigCollection().loadFromFile(contigs_file)
# contigs.loadFromFasta(open(contigs_file, "r"), num_names=True)
# contigs = contigs.filter(lambda contig: contig.id not in nonunique and len(contig) > params.k + 20)
sys.stdout.info("Created", len(contigs), "initial contigs")
if not all_unique or force_unique is not None:
sys.stdout.info("Polishing contigs")
polished_contigs = polisher.polishMany(reads, list(contigs.unique()))
contigs = ContigCollection().addAll(polished_contigs)
else:
sys.stdout.info("Skipping contig polishing step since manual unique contig initialization was used")
return contigs