Revision c3bc4ccfa592b1855aa783a9d57c7569d1eb5577 authored by Tatiana Malygina on 26 March 2019, 14:51:44 UTC, committed by Tatiana Malygina on 26 March 2019, 14:51:44 UTC
1 parent 9e0e4e5
scaffolder.py
#(c) 2013-2014 by Authors
#This file is a part of Ragout program.
#Released under the BSD license (see LICENSE file)
"""
This module assembles contigs into scaffolds with respect
to given adjacencies. Also, it outputs scaffolds in different
formats
"""
from collections import defaultdict, namedtuple
from itertools import repeat
import os
import copy
import logging
from ragout.shared.debug import DebugConfig
from ragout.shared.datatypes import (Contig, Scaffold, Link,
output_scaffolds_premutations,
output_permutations)
from ragout.scaffolder.output_generator import output_links
logger = logging.getLogger()
debugger = DebugConfig.get_instance()
def build_scaffolds(adjacencies, perm_container, debug_output=True,
correct_distances=True):
"""
Assembles scaffolds wrt to inferred adjacencies
"""
if debug_output:
logger.debug("Building scaffolds")
contigs, contig_index = _make_contigs(perm_container)
scaffolds = _extend_scaffolds(adjacencies, contigs, contig_index,
correct_distances)
num_contigs = sum(map(lambda s: len(s.contigs), scaffolds))
logger.debug("{0} contigs were joined into {1} scaffolds"
.format(num_contigs, len(scaffolds)))
if debugger.debugging and debug_output:
links_out = os.path.join(debugger.debug_dir, "scaffolder.links")
output_links(scaffolds, links_out)
contigs_out = os.path.join(debugger.debug_dir, "scaffolder_contigs.txt")
output_permutations(perm_container.target_perms, contigs_out)
perms_out = os.path.join(debugger.debug_dir, "scaffolder_scaffolds.txt")
output_scaffolds_premutations(scaffolds, perms_out)
return scaffolds
def assign_scaffold_names(scaffolds, perm_container, ref_genome):
"""
Names scaffolds according to homology to a chosen reference genome.
Also ensures that scaffolds and corresponding reference chromosomes
have the same strand.
"""
MIN_RATE = 0.1
PREFIX = "chr"
chr_index = {}
for perm in perm_container.ref_perms:
if perm.genome_name == ref_genome:
for block in perm.blocks:
chr_index[block.block_id] = perm.chr_name, block.sign
assigned_names = {}
need_rev_compl = {}
for scf in scaffolds:
scf_index = defaultdict(int)
sign_agreement = 0
total = 0
for contig in scf.contigs:
for block in contig.perm.blocks:
if block.block_id in chr_index:
chrom, sign = chr_index[block.block_id]
scf_index[chrom] += 1
total += 1
sign_agreement += int(sign == block.sign * contig.sign)
name_str = PREFIX
for chrom in sorted(scf_index, key=scf_index.get, reverse=True):
if scf_index[chrom] > MIN_RATE * total:
name_str += "_" + chrom
else:
break
assigned_names[scf] = name_str
need_rev_compl[scf] = sign_agreement < total / 2
#in case of same names
same_names = defaultdict(list)
for scf, name in assigned_names.items():
same_names[name].append(scf)
for name, scf_list in same_names.items():
scf_list.sort(key=lambda s: len(s.contigs), reverse=True)
unlocalized = scf_list[1:]
for scf in unlocalized:
assigned_names[scf] += "_unlocalized"
if len(unlocalized) > 1:
for num, scf in enumerate(unlocalized):
assigned_names[scf] += "." + str(num + 1)
for scf in scaffolds:
scf.name = assigned_names[scf]
if need_rev_compl[scf]:
new_contigs = map(lambda c: c.reverse_copy(), scf.contigs)[::-1]
for i in xrange(len(new_contigs) - 2):
new_contigs[i].link = new_contigs[i + 1].link
new_contigs[-1].link = Link(0, [])
scf.contigs = new_contigs
def _extend_scaffolds(adjacencies, contigs, contig_index, correct_distances):
"""
Assembles contigs into scaffolds
"""
scaffolds = []
visited = set()
counter = [0]
def extend_scaffold(contig):
visited.add(contig)
scf_name = "ragout-scaffold-{0}".format(counter[0])
counter[0] += 1
scf = Scaffold.with_contigs(scf_name, contig.left_end(),
contig.right_end(), [contig])
already_complete = (scf.right in adjacencies and
adjacencies[scf.right].block == scf.left and
adjacencies[scf.right].infinity)
if already_complete:
scaffolds.append(scf)
return
#go right
while scf.right in adjacencies and not adjacencies[scf.right].infinity:
adj_block = adjacencies[scf.right].block
adj_distance = adjacencies[scf.right].distance
adj_supporting_genomes = adjacencies[scf.right].supporting_genomes
contig = contig_index[abs(adj_block)]
if contig in visited:
break
if adj_block in [contig.left_end(), contig.right_end()]:
if contig.left_end() == adj_block:
scf.contigs.append(contig)
else:
scf.contigs.append(contig.reverse_copy())
flank = scf.contigs[-2].right_gap() + scf.contigs[-1].left_gap()
gap = adj_distance - flank if correct_distances else adj_distance
scf.contigs[-2].link = Link(gap, adj_supporting_genomes)
scf.right = scf.contigs[-1].right_end()
visited.add(contig)
continue
break
#go left
while scf.left in adjacencies and not adjacencies[scf.left].infinity:
adj_block = adjacencies[scf.left].block
adj_distance = adjacencies[scf.left].distance
adj_supporting_genomes = adjacencies[scf.left].supporting_genomes
contig = contig_index[abs(adj_block)]
if contig in visited:
break
if adj_block in [contig.right_end(), contig.left_end()]:
if contig.right_end() == adj_block:
scf.contigs.insert(0, contig)
else:
scf.contigs.insert(0, contig.reverse_copy())
flank = scf.contigs[0].right_gap() + scf.contigs[1].left_gap()
gap = adj_distance - flank if correct_distances else adj_distance
scf.contigs[0].link = Link(gap, adj_supporting_genomes)
scf.left = scf.contigs[0].left_end()
visited.add(contig)
continue
break
if len(scf.contigs) > 1:
scaffolds.append(scf)
for contig in contigs:
if contig not in visited:
extend_scaffold(contig)
return scaffolds
def _make_contigs(perm_container):
"""
A helper function to make Contig structures
"""
contigs = []
index = {}
for perm in perm_container.target_perms:
assert len(perm.blocks)
contigs.append(Contig.with_perm(perm))
for block in perm.blocks:
assert block.block_id not in index
index[block.block_id] = contigs[-1]
return contigs, index
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