def __getitem__(self, idxs):
if isinstance(idxs, tuple):
if len(idxs) == 3 or len(idxs) == 4:
# interpret idxs as genomic interval
idxs = GenomicInterval(*idxs)
else:
raise ValueError('idxs cannot be interpreted as genomic interval.'
' use (chr, start, end) or (chr, start, end, strand)')
if isinstance(idxs, int):
idxs = [idxs]
elif isinstance(idxs, slice):
idxs = range(idxs.start if idxs.start else 0,
idxs.stop if idxs.stop else len(self),
idxs.step if idxs.step else 1)
elif isinstance(idxs, GenomicInterval):
if not self.garray._full_genome_stored:
raise ValueError('Indexing with GenomicInterval only possible '
'when the whole genome (or chromosome) was loaded')
data = np.zeros((1, idxs.length - self.garray.order + 1))
data[0] = self._getsingleitem(idxs)
# accept a genomic interval directly
data = as_onehot(data,
self.garray.order,
self._alphabetsize)
for transform in self.transformations:
data = transform(data)
if not self._channel_last:
data = np.transpose(data, (0, 3, 1, 2))
return data
try:
iter(idxs)
except TypeError:
raise IndexError('Bioseq.__getitem__: '
+ 'index must be iterable')
data = as_onehot(self.iseq4idx(idxs), self.garray.order,
self._alphabetsize)
for transform in self.transformations:
data = transform(data)
if not self._channel_last:
data = np.transpose(data, (0, 3, 1, 2))
return data
def __getitem__(self, idxs):
if isinstance(idxs, tuple):
if len(idxs) == 3 or len(idxs) == 4:
# interpret idxs as genomic interval
idxs = Interval(*idxs)
else:
raise ValueError(
'Cannot interpret genomic interval.'
' Use (chr, start, end) or (chr, start, end, strand)')
if isinstance(idxs, int):
idxs = [idxs]
elif isinstance(idxs, slice):
idxs = range(idxs.start if idxs.start else 0,
idxs.stop if idxs.stop else len(self),
idxs.step if idxs.step else 1)
elif isinstance(idxs, Interval):
if not self.garray._full_genome_stored:
raise ValueError('Indexing with Interval '
'requires store_whole_genome=True.')
data = np.zeros((1, idxs.length - self.garray.order + 1))
data[0] = self._getsingleitem(idxs)
# accept a genomic interval directly
data = as_onehot(data, self.garray.order, self._alphabetsize)
return data
try:
iter(idxs)
except TypeError:
raise IndexError('Bioseq.__getitem__: ' + 'index must be iterable')
data = as_onehot(self.iseq4idx(idxs), self.garray.order,
self._alphabetsize)
return data
def flow(self):
"""Data flow generator."""
refs = np.zeros(
(self.batch_size, self.binsize - self.bioseq.garray.order + 1, 1,
pow(self.bioseq._alphabetsize, self.bioseq.garray.order)))
alts = np.zeros_like(refs)
vcf = VariantFile(self.variants).fetch()
try:
while True:
# construct genomic region
names = []
chroms = []
poss = []
rallele = []
aallele = []
ibatch = 0
while ibatch < self.batch_size:
rec = next(vcf)
if not self.is_compatible(rec):
continue
start = rec.pos - self.binsize // 2 + (1 if self.binsize %
2 == 0 else 0) - 1
end = rec.pos + self.binsize // 2
if start < 0:
continue
names.append(rec.id if rec.id is not None else '')
chroms.append(rec.chrom)
poss.append(rec.pos - 1)
rallele.append(rec.ref.upper())
aallele.append(rec.alts[0].upper())
iref = self.bioseq._getsingleitem(
Interval(rec.chrom, start, end)).copy()
ref = as_onehot(iref[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
refs[ibatch] = ref
#mutate the position with the variant
# only support single nucleotide variants at the moment
for o in range(self.bioseq.garray.order):
irefbase = iref[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize % 2 == 0 else 1)]
irefbase = irefbase // pow(self.bioseq._alphabetsize,
o)
irefbase = irefbase % self.bioseq._alphabetsize
if NMAP[rec.ref.upper()] != irefbase:
self.logger.info(
'VCF reference and reference genome not compatible.'
'Expected reference {}, but VCF indicates {}.'.
format(irefbase, NMAP[rec.ref.upper()]) +
'VCF-Record: {}:{}-{}>{};{}. Skipped.'.format(
rec.chrom, rec.pos, rec.ref, rec.alts[0],
rec.id))
else:
replacement = (NMAP[rec.alts[0].upper()] -
NMAP[rec.ref.upper()]) * \
pow(self.bioseq._alphabetsize, o)
iref[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize %
2 == 0 else 1)] += replacement
alt = as_onehot(iref[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
alts[ibatch] = alt
ibatch += 1
yield names, chroms, poss, rallele, aallele, refs, alts
except StopIteration:
refs = refs[:ibatch]
alts = alts[:ibatch]
yield names, chroms, poss, rallele, aallele, refs, alts
def flow(self):
"""Data flow generator."""
refs = np.zeros(
(self.batch_size, self.binsize - self.bioseq.garray.order + 1, 1,
pow(self.bioseq._alphabetsize, self.bioseq.garray.order)))
alts = np.zeros_like(refs)
# get variants
vcf = VariantFile(self.variants).fetch()
def _get_replacement(new_nucleotide, previous_nucleotide, o):
# helper function for replacing old with new nucleotides
return (new_nucleotide - previous_nucleotide) * \
pow(self.bioseq._alphabetsize, o)
# annotation is used to inform about the strandedness
# to evaluate the variant
if self.annotation is not None:
varbed = BedTool(self.variants)
n_vcf_fields = len(varbed[0].fields)
vcf_strand_augment = iter(
varbed.intersect(self.annotation, loj=True))
try:
while True:
# construct genomic region
names = []
chroms = []
poss = []
rallele = []
aallele = []
ibatch = 0
# prepare mini-batches of variants
while ibatch < self.batch_size:
rec = next(vcf)
rec_strandedness = '+'
if self.annotation is not None:
rec_aug = next(vcf_strand_augment)
rec_strandedness = '-' if '-' in rec_aug[
n_vcf_fields:] else '+'
if not self.is_compatible(rec):
continue
start, end = self.get_interval(rec)
names.append(rec.id if rec.id is not None else '')
chroms.append(rec.chrom)
poss.append(rec.pos - 1)
rallele.append(rec.ref.upper())
aallele.append(rec.alts[0].upper())
# obtain the nucleotide indices around the variant
iref = self.bioseq._getsingleitem(
Interval(rec.chrom, start, end)).copy()
ialt = iref.copy()
for o in range(self.bioseq.garray.order):
# in the loop we adjust the original DNA sequence
# by using the alternative alleele instead
#
# the loop is required for the higher-order nucleotide representation
# in which a single variant position affects multiple
# mutually overlapping positions in the one-hot encoding
#
# furthermore, the alternative alleele is only set if
# the reference alleele matches with the reference genome.
# unless the ignore_reference_match option was used.
# this is the positions at which to change the nucleotide
position_to_change = self.binsize//2 + o - \
self.bioseq.garray.order + \
(0 if self.binsize%2 == 0 else 1)
# determine the reference nucleotide
# this would be just irefbase itself for order=1
# but for higher-order representation it needs to
# be determined. e.g. for TT for order=2 would be irefbase==15
# which should give the nucleotides 3, 3
irefbase = iref[position_to_change]
irefbase = irefbase // pow(self.bioseq._alphabetsize,
o)
irefbase = irefbase % self.bioseq._alphabetsize
if self.ignore_reference_match:
# process the variant even if
# it does not match with the reference base
# replace nucleotides in the reference
# and in the alternative alleele
iref[position_to_change] += _get_replacement(
NMAP[rec.ref.upper()], irefbase, o)
ialt[position_to_change] += _get_replacement(
NMAP[rec.alts[0].upper()], irefbase, o)
continue
if NMAP[rec.ref.upper()] != irefbase:
self.logger.info(
'VCF reference and reference genome not compatible.'
'Expected reference {}, but VCF indicates {}.'.
format(irefbase, NMAP[rec.ref.upper()]) +
'VCF-Record: {}:{}-{}>{};{}. Skipped.'.format(
rec.chrom, rec.pos, rec.ref, rec.alts[0],
rec.id))
else:
# at this point, it is ensured that the VCF reference
# agrees with the reference genome.
# keep the reference as it is, only change
# the alternative alleele
ialt[position_to_change] += _get_replacement(
NMAP[rec.alts[0].upper()],
NMAP[rec.ref.upper()], o)
# if the strandedness is negative (from the annotation)
# the DNA sequences are reverse complemented
if rec_strandedness == '-':
ialt = self.bioseq._revcomp(ialt)
iref = self.bioseq._revcomp(iref)
alt = as_onehot(ialt[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
alts[ibatch] = alt
ref = as_onehot(iref[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
refs[ibatch] = ref
ibatch += 1
yield names, chroms, poss, rallele, aallele, refs, alts
except StopIteration:
refs = refs[:ibatch]
alts = alts[:ibatch]
yield names, chroms, poss, rallele, aallele, refs, alts
def flow(self):
"""Data flow generator."""
refs = np.zeros(
(self.batch_size, self.binsize - self.bioseq.garray.order + 1, 1,
pow(self.bioseq._alphabetsize, self.bioseq.garray.order)))
alts = np.zeros_like(refs)
vcf = VariantFile(self.variants).fetch()
if self.annotation is not None:
varbed = BedTool(self.variants)
n_vcf_fields = len(varbed[0].fields)
vcf_strand_augment = iter(
varbed.intersect(self.annotation, loj=True))
try:
while True:
# construct genomic region
names = []
chroms = []
poss = []
rallele = []
aallele = []
ibatch = 0
while ibatch < self.batch_size:
rec = next(vcf)
rec_strandedness = '+'
if self.annotation is not None:
rec_aug = next(vcf_strand_augment)
rec_strandedness = '-' if '-' in rec_aug[
n_vcf_fields:] else '+'
if not self.is_compatible(rec):
continue
start, end = self.get_interval(rec)
names.append(rec.id if rec.id is not None else '')
chroms.append(rec.chrom)
poss.append(rec.pos - 1)
rallele.append(rec.ref.upper())
aallele.append(rec.alts[0].upper())
iref = self.bioseq._getsingleitem(
Interval(rec.chrom, start, end)).copy()
ialt = iref.copy()
for o in range(self.bioseq.garray.order):
irefbase = iref[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize % 2 == 0 else 1)]
irefbase = irefbase // pow(self.bioseq._alphabetsize,
o)
irefbase = irefbase % self.bioseq._alphabetsize
if self.ignore_reference_match:
# process the variant even if
# it does not match with the reference base
replacement = (NMAP[rec.ref.upper()] -
irefbase) * \
pow(self.bioseq._alphabetsize, o)
iref[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize %
2 == 0 else 1)] += replacement
replacement = (NMAP[rec.alts[0].upper()] -
irefbase) * \
pow(self.bioseq._alphabetsize, o)
ialt[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize %
2 == 0 else 1)] += replacement
continue
if NMAP[rec.ref.upper()] != irefbase:
self.logger.info(
'VCF reference and reference genome not compatible.'
'Expected reference {}, but VCF indicates {}.'.
format(irefbase, NMAP[rec.ref.upper()]) +
'VCF-Record: {}:{}-{}>{};{}. Skipped.'.format(
rec.chrom, rec.pos, rec.ref, rec.alts[0],
rec.id))
else:
# at this point, it is ensured that the VCF reference
# agrees with the reference genome.
replacement = (NMAP[rec.alts[0].upper()] -
NMAP[rec.ref.upper()]) * \
pow(self.bioseq._alphabetsize, o)
ialt[self.binsize // 2 + o -
self.bioseq.garray.order +
(0 if self.binsize %
2 == 0 else 1)] += replacement
if rec_strandedness == '-':
ialt = self.bioseq._revcomp(ialt)
iref = self.bioseq._revcomp(iref)
alt = as_onehot(ialt[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
alts[ibatch] = alt
ref = as_onehot(iref[None, :], self.bioseq.garray.order,
self.bioseq._alphabetsize)
refs[ibatch] = ref
ibatch += 1
yield names, chroms, poss, rallele, aallele, refs, alts
except StopIteration:
refs = refs[:ibatch]
alts = alts[:ibatch]
yield names, chroms, poss, rallele, aallele, refs, alts
