def test_round_trip_vcf(self, test_datum_name):
# Round-trip variants through writing and reading:
# 1. Read variants v1 from VcfReader;
# 2. Write v1 to vcf using our VcfWriter;
# 3. Read back in using VcfReader -- v2;
# 4. compare v1 and v2.
in_file = test_utils.genomics_core_testdata(test_datum_name)
out_file = test_utils.test_tmpfile('output_' + test_datum_name)
v1_reader = vcf.VcfReader(in_file)
v1_records = list(v1_reader.iterate())
self.assertTrue(v1_records, 'Reader failed to find records')
header = copy.deepcopy(v1_reader.header)
writer_options = variants_pb2.VcfWriterOptions()
with vcf_writer.VcfWriter.to_file(out_file, header,
writer_options) as writer:
for record in v1_records:
writer.write(record)
v2_reader = vcf.VcfReader(out_file)
v2_records = list(v2_reader.iterate())
self.assertEqual(v1_records, v2_records,
'Round-tripped variants not as expected')
def setUp(self):
self.sites_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_sites.vcf'),
use_index=False)
self.samples_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_samples.vcf.gz'),
use_index=True)
def test_vcf_query(self):
tabix.build_index(self.output_file)
self.input_reader = vcf.VcfReader(self.input_file)
self.output_reader = vcf.VcfReader(self.output_file)
range1 = ranges.parse_literal('chr3:100,000-500,000')
self.assertEqual(list(self.input_reader.query(range1)),
list(self.output_reader.query(range1)))
def test_headerless_vcf(self):
"""Writes a headerless vcf and reads it back out."""
test_vcf = test_utils.genomics_core_testdata('test_sites.vcf')
output_vcf = test_utils.test_tmpfile('output.vcf')
expected_variants = []
with vcf.VcfReader(test_vcf) as reader:
with vcf.VcfWriter(
output_vcf, header=reader.header, exclude_header=True) as writer:
for record in reader:
expected_variants.append(record)
writer.write(record)
with vcf.VcfReader(output_vcf, header=reader.header) as actual_reader:
self.assertEqual(expected_variants, list(actual_reader))
def test_roundtrip(self,
expected_infos,
expected_fmt,
expected_fmt1,
expected_fmt2,
reader_excluded_info=None,
reader_excluded_format=None,
writer_excluded_info=None,
writer_excluded_format=None):
expected_records = [
record.format(info=info, fmt=expected_fmt, efmts1=e1,
efmts2=e2) for record, info, e1, e2 in zip(
self.record_format_strings, expected_infos,
expected_fmt1, expected_fmt2)
]
expected = self.header + ''.join(expected_records)
with vcf.VcfReader(
test_utils.genomics_core_testdata('test_py_roundtrip.vcf'),
excluded_info_fields=reader_excluded_info,
excluded_format_fields=reader_excluded_format) as reader:
records = list(reader.iterate())
output_path = test_utils.test_tmpfile('test_roundtrip_tmpfile.vcf')
with vcf.VcfWriter(
output_path,
header=reader.header,
excluded_info_fields=writer_excluded_info,
excluded_format_fields=writer_excluded_format) as writer:
for record in records:
writer.write(record)
with open(output_path) as f:
actual = f.read()
self.assertEqual(actual, expected)
def test_c_reader(self):
self.assertNotEqual(self.sites_reader.c_reader, 0)
self.assertNotEqual(self.samples_reader.c_reader, 0)
tfrecord_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_samples.vcf.golden.tfrecord'))
self.assertNotEqual(tfrecord_reader.c_reader, 0)
def make_ngs_error_examples(ref_path, vcf_path, bam_path):
""" Yields tf.Example for training a ML model.
Each tf.Example contains
relevant features aboout the ngs read.
Args:
ref_path: str. A path to an indexed fasta file.
vcf_path: str. A path to an indexed VCF file.
bam_path: str. A path to an SAM/BAM file.
Yields:
A tuple (example, ngs_read_length, has_error), where example is a
tf.Example, ngs_read_length is the length of the read generated by the
sequencer, and has_error is a boolean specifying whether the example
contains a read error.
"""
# Create a ref_reader backed by ref.
ref_reader = fasta.IndexedFastaReader(ref_path)
# Create a vcf_reader backed by vcf.
vcf_reader = vcf.VcfReader(vcf_path)
# Create a sam_reader backed by bam. Provide an empty ReadRequirements
# proto to the reader so it enables standard filtering based on the default
# values of ReadRequirements. Also explicitly allow the reader to access an
# unindexed BAM, so only the iterate() function is enabled.
read_requirements = reads_pb2.ReadRequirements()
sam_reader = sam.SamReader(bam_path, read_requirements=read_requirements)
# All our readers and writers are context managers, so use the `with`
# construct to open all of the inputs/outputs and close them when we are done
# looping over our reads.
with ref_reader, vcf_reader, sam_reader:
# Loop over the reads in our BAM file:
for read in sam_reader.iterate():
# Get the Range proto describing the chrom/start/stop spanned by our read.
assert len(read.alignment.cigar) > 0
first_cigar = read.alignment.cigar[0]
# If the first cigar is a CLIP_SOFT, the start of sequence is the cigar
# operation length before the alignment position.
start = read.alignment.position.position
if first_cigar.operation == cigar_pb2.CigarUnit.CLIP_SOFT:
start -= first_cigar.operation_length
read_range = ranges.make_range(read.alignment.position.reference_name,
start, start + len(read.aligned_sequence))
# Get all of the variants that overlap our read range.
variants = list(vcf_reader.query(read_range))
# Get the reference bases spanned by our read.
ref_bases = ref_reader.query(read_range)
# Check that we can use our read for generating an example.
if is_usable_training_example(read, variants, ref_bases):
# Convert read and ref_bases to a tf.Example with make_example.
yield make_example(read, ref_bases), len(read.aligned_sequence), (
read.aligned_sequence != ref_bases)
def test_main(self):
in_fname = test_utils.genomics_core_testdata('test_vaf.vcf')
out_fname = test_utils.test_tmpfile('output.vcf')
filter_vcf.main(['filter_vcf', in_fname, out_fname])
with vcf.VcfReader(out_fname) as reader:
variants = list(reader)
self.assertEqual(3, len(variants))
self.assertEqual(['DogSNP4', 'DogSNP5', 'DogSNP6'],
[v.names[0] for v in variants])
for v in variants:
self.assertTrue(v.quality > 3.01)
def main(argv):
del argv
priors = map(float, FLAGS.genotype_priors)
sump = sum(priors)
log_priors = [math.log10(x / sump) for x in priors]
with vcf.VcfReader(FLAGS.input_vcf) as reader:
with vcf.VcfWriter(FLAGS.output_vcf, header=reader.header) as writer:
for variant in reader:
recall_variant(log_priors, variant)
# TODO(thomaswc): Also update the variant's quality.
writer.write(variant)
def main(argv):
if len(argv) != 3:
print('Usage: {} <input_vcf> <output_vcf>'.format(argv[0]))
sys.exit(-1)
in_vcf = argv[1]
out_vcf = argv[2]
# Please try to keep the following part in sync with the documenation in
# g3doc/overview.md.
with vcf.VcfReader(in_vcf, use_index=False) as reader:
print('Sample names in VCF: ', ' '.join(reader.header.sample_names))
with vcf.VcfWriter(out_vcf, header=reader.header) as writer:
for variant in reader:
if variant.quality > 3.01:
writer.write(variant)
def main(argv):
if len(argv) != 3:
print('Usage: {} <input_ref> <input_vcf>'.format(argv[0]))
sys.exit(-1)
in_ref = argv[1]
in_vcf = argv[2]
with fasta.RefFastaReader(in_ref) as ref_reader:
with vcf.VcfReader(in_vcf, use_index=False) as vcf_reader:
validate_contigs(ref_reader.header.contigs, vcf_reader.header.contigs)
for variant in vcf_reader:
validate_variant(ref_reader, variant)
# VCF is valid!
print('Reference and VCF are compatible.')
sys.exit(0)
def test_main(self):
in_fname = test_utils.genomics_core_testdata('test_allele_depth.vcf')
out_fname = test_utils.test_tmpfile('output.vcf')
add_ad_to_vcf.main(['add_ad_to_vcf', in_fname, out_fname])
with vcf.VcfReader(out_fname, use_index=False) as reader:
info_ids = [info.id for info in reader.header.infos]
self.assertTrue('AD' in info_ids)
variant1 = next(reader)
self.assertEqual([3, 3], variant_utils.get_info(variant1, 'AD', reader))
variant2 = next(reader)
self.assertEqual([30, 44], variant_utils.get_info(variant2, 'AD', reader))
variant3 = next(reader)
self.assertEqual([15, 4], variant_utils.get_info(variant3, 'AD', reader))
variant4 = next(reader)
self.assertEqual([2, 4], variant_utils.get_info(variant4, 'AD', reader))
variant5 = next(reader)
self.assertEqual([24, 2], variant_utils.get_info(variant5, 'AD', reader))
def main(argv):
if len(argv) != 3:
print('Usage: %s <input_vcf> <output_vcf>' % argv[0])
sys.exit(-1)
in_vcf = argv[1]
out_vcf = argv[2]
with vcf.VcfReader(in_vcf) as reader:
if 'AD' in [info.id for info in reader.header.infos]:
print('%s already contains AD field.' % in_vcf)
sys.exit(-1)
out_header = reader.header
out_header.infos.extend([vcf_constants.reserved_info_field('AD')])
with vcf.VcfWriter(out_vcf, header=out_header) as writer:
for variant in reader:
variant_utils.set_info(variant, 'AD', get_variant_ad(variant),
writer)
writer.write(variant)
def make_ngs_examples(hparams):
"""Generator function that yields training, evaluation and test examples."""
ref_reader = fasta.IndexedFastaReader(input_path=hparams.ref_path)
vcf_reader = vcf.VcfReader(input_path=hparams.vcf_path)
read_requirements = reads_pb2.ReadRequirements()
sam_reader = sam.SamReader(input_path=hparams.bam_path,
read_requirements=read_requirements)
# Use a separate SAM reader to query for reads falling in the pileup range.
sam_query_reader = sam.SamReader(input_path=hparams.bam_path,
read_requirements=read_requirements)
used_pileup_ranges = set()
with ref_reader, vcf_reader, sam_reader, sam_query_reader:
for read in sam_reader:
# Check that read has cigar string present and allowed alignment.
if not read.alignment.cigar:
print('Skipping read, no cigar alignment found')
continue
if not has_allowed_alignment(read):
continue
# Obtain window that will be used to construct an example.
read_range = utils.read_range(read)
ref = ref_reader.query(region=read_range)
pileup_range = get_pileup_range(hparams, read, read_range, ref)
# Do not construct multiple examples with the same pileup range.
pileup_range_serialized = pileup_range.SerializeToString()
if pileup_range_serialized in used_pileup_ranges:
continue
used_pileup_ranges.add(pileup_range_serialized)
# Get reference sequence, reads, and truth variants for the pileup range.
pileup_reads = list(sam_query_reader.query(region=pileup_range))
pileup_ref = ref_reader.query(region=pileup_range)
pileup_variants = list(vcf_reader.query(region=pileup_range))
if is_usable_example(pileup_reads, pileup_variants, pileup_ref):
yield make_example(hparams, pileup_reads, pileup_ref,
pileup_range)
def main(argv):
if len(argv) != 2:
print('Usage: {} <input_vcf>'.format(argv[0]))
sys.exit(-1)
in_vcf = argv[1]
total = 0
by_type = collections.defaultdict(int)
by_ref = collections.defaultdict(int)
with vcf.VcfReader(in_vcf) as reader:
for variant in reader:
total += 1
by_type[variant_utils.variant_type(variant)] += 1
by_ref[variant.reference_name] += 1
print('# variants: {}'.format(total))
print('# ref variants: {}'.format(by_type[variant_utils.VariantType.ref]))
print('# SNP variants: {}'.format(by_type[variant_utils.VariantType.snp]))
print('# indel variants: {}'.format(by_type[variant_utils.VariantType.indel]))
for k, v in sorted(by_ref.items()):
print('# variants in {}: {}'.format(k, v))
def test_header_format_mixed_order(self):
"""Tests reading a VCF with unconventional FORMAT field definition.
Tests reading a VCF in which the properties of the format
fields are defined in mixed order in the header. For example,
##FORMAT=<ID=GT,Type=String,Number=1,Description="GT description">
(In normal VCFs "Number" should come before "Type".)
"""
with vcf.VcfReader(
test_utils.genomics_core_testdata(
'header_format_mixed_order.vcf')) as vreader:
formats = vreader.header.formats
variants = list(vreader)
self.assertLen(formats, 1)
self.assertEqual(formats[0].id, 'GT')
self.assertEqual(formats[0].number, '1')
self.assertEqual(formats[0].type, 'String')
self.assertEqual(formats[0].description, 'GT description')
self.assertLen(variants, 2)
self.assertEqual(variants[0].calls[0].genotype, [0, 1])
self.assertEqual(variants[1].calls[0].genotype, [1, 1])
def setUp(self):
self.sites_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_sites.vcf'))
self.samples_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_samples.vcf.gz'))
def setUp(self):
self.vcf_reader = vcf.VcfReader(
test_utils.genomics_core_testdata('test_sites.vcf'))
self.cache = self.vcf_reader.field_access_cache
def make_ngs_error_examples(ref_path,
vcf_path,
bam_path,
examples_out_path,
max_reads=None):
"""Driver program for ngs_errors.
See module description for details.
Args:
ref_path: str. A path to an indexed fasta file.
vcf_path: str. A path to an indexed VCF file.
bam_path: str. A path to an SAM/BAM file.
examples_out_path: str. A path where we will write out examples.
max_reads: int or None. If not None, we will emit at most max_reads examples
to examples_out_path.
"""
# Create a ref_reader backed by ref.
ref_reader = fasta.IndexedFastaReader(ref_path)
# Create a vcf_reader backed by vcf.
vcf_reader = vcf.VcfReader(vcf_path)
# Create a sam_reader backed by bam. Provide an empty ReadRequirements
# proto to the reader so it enables standard filtering based on the default
# values of ReadRequirements. Also explicitly allow the reader to access an
# unindexed BAM, so only the iterate() function is enabled.
read_requirements = reads_pb2.ReadRequirements()
sam_reader = sam.SamReader(bam_path, read_requirements=read_requirements)
# Create our TFRecordWriter where we'll send our tf.Examples.
examples_out = genomics_writer.TFRecordWriter(examples_out_path)
# All our readers and writers are context managers, so use the `with`
# construct to open all of the inputs/outputs and close them when we are done
# looping over our reads.
n_examples = 0
with ref_reader, vcf_reader, sam_reader, examples_out:
# Loop over the reads in our BAM file:
for i, read in enumerate(sam_reader.iterate(), start=1):
# Get the Range proto describing the chrom/start/stop spanned by our read.
read_range = utils.read_range(read)
# Get all of the variants that overlap our read range.
variants = list(vcf_reader.query(read_range))
# Get the reference bases spanned by our read.
ref_bases = ref_reader.query(read_range)
# Check that we can use our read for generating an example.
if is_usable_training_example(read, variants, ref_bases):
n_examples += 1
# Convert read and ref_bases to a tf.Example with make_example.
example = make_example(read, ref_bases)
# And write it out to our TFRecord output file.
examples_out.write(example)
# Do a bit of convenient logging. This is very verbose if we convert a
# lot of reads...
logging.info((
'Added an example for read %s (span=%s) with cigar %s [%d added '
'of %d total reads]'), read.fragment_name,
ranges.to_literal(read_range),
cigar.format_cigar_units(read.alignment.cigar),
n_examples, i)
if max_reads is not None and n_examples >= max_reads:
return
from nucleus.io import vcf
r = vcf.VcfReader('NA12878_calls.vcf.gz')
#r = vcf.VcfReader('test_samples.vcf')
#for v in r:
# print(v.start)
