def generate_reads(args):
"""Main function for the `iss generate` submodule
This submodule generates reads from an ErrorModel and write them to
args.output + _R(1|2).fastq
Args:
args (object): the command-line arguments from argparse
"""
logger = logging.getLogger(__name__)
logger.debug('iss version %s' % __version__)
logger.debug('Using verbose logger')
try: # try to import and load the correct error model
logger.info('Starting iss generate')
logger.info('Using %s ErrorModel' % args.mode)
if args.seed:
logger.info('Setting random seed to %i' % args.seed)
random.seed(args.seed)
np.random.seed(args.seed)
if args.mode == 'kde':
from iss.error_models import kde
if args.model is None:
logger.error('--model is required in --mode kde')
sys.exit(1)
elif args.model.lower() == 'hiseq':
npz = os.path.join(os.path.dirname(__file__), 'profiles/HiSeq')
elif args.model.lower() == 'novaseq':
npz = os.path.join(os.path.dirname(__file__),
'profiles/NovaSeq')
elif args.model.lower() == 'miseq':
npz = os.path.join(os.path.dirname(__file__), 'profiles/MiSeq')
else:
npz = args.model
err_mod = kde.KDErrorModel(npz)
elif args.mode == 'basic':
if args.model is not None:
logger.warning('--model %s will be ignored in --mode %s' %
(args.model, args.mode))
from iss.error_models import basic
err_mod = basic.BasicErrorModel()
elif args.mode == 'perfect':
if args.model is not None:
logger.warning('--model %s will be ignored in --mode %s' %
(args.model, args.mode))
from iss.error_models import perfect
err_mod = perfect.PerfectErrorModel()
except ImportError as e:
logger.error('Failed to import ErrorModel module: %s' % e)
sys.exit(1)
try: # try to read genomes and concatenate --genomes and --ncbi genomes
if args.genomes or args.draft or args.ncbi:
genome_files = []
if args.genomes:
genome_files.extend(args.genomes)
if args.draft:
logger.warning('--draft is in early experimental stage.')
logger.warning(
'disabling --abundance_file, --coverage and --n_genomes')
logger.warning('Defaulting to --abundance.')
genome_files.extend(args.draft)
if args.ncbi and args.n_genomes_ncbi:
util.genome_file_exists(args.output + '_ncbi_genomes.fasta')
total_genomes_ncbi = []
try:
assert len(*args.ncbi) == len(*args.n_genomes_ncbi)
except AssertionError as e:
logger.error(
'--ncbi and --n_genomes_ncbi of unequal lengths. \
Aborting')
sys.exit(1)
# this is py3 only
# for g, n in zip(*args.ncbi, *args.n_genomes):
# py2 compatibilty workaround
# TODO switch to the more elegant solution when we drop python2
args.ncbi = [x for y in args.ncbi for x in y]
args.n_genomes_ncbi = [
x for y in args.n_genomes_ncbi for x in y
]
for g, n in zip(args.ncbi, args.n_genomes_ncbi):
genomes_ncbi = download.ncbi(
g, n, args.output + '_ncbi_genomes.fasta')
genome_files.append(genomes_ncbi)
if args.ncbi and not args.n_genomes_ncbi:
logger.error(
'--ncbi/-k requires --n_genomes_ncbi/-U. Aborting.')
sys.exit(1)
else:
logger.error("One of --genomes/-g, --draft, --ncbi/-k is required")
sys.exit(1)
genome_file = args.output + '.iss.tmp.genomes.fasta'
util.concatenate(genome_files, output=genome_file)
# for n_genomes we use reservoir sampling to draw random genomes
# from the concatenated genome file. We then override the file.
if args.n_genomes and not args.draft and not args.ncbi:
genome_count = util.count_records(genome_file)
genome_files = [
genome
for genome in util.reservoir(SeqIO.parse(genome_file, 'fasta'),
genome_count, args.n_genomes)
]
SeqIO.write(genome_files, genome_file, 'fasta')
assert os.stat(genome_file).st_size != 0
f = open(genome_file, 'r')
with f: # count the number of records
genome_list = util.count_records(f)
except IOError as e:
logger.error('Failed to open genome(s) file:%s' % e)
sys.exit(1)
except AssertionError as e:
logger.error('Genome(s) file seems empty: %s' % genome_file)
sys.exit(1)
except KeyboardInterrupt as e:
logger.error('iss generate interrupted: %s' % e)
sys.exit(1)
else:
abundance_dispatch = {
'uniform': abundance.uniform,
'halfnormal': abundance.halfnormal,
'exponential': abundance.exponential,
'lognormal': abundance.lognormal,
'zero_inflated_lognormal': abundance.zero_inflated_lognormal
}
# read the abundance file
if args.abundance_file and not args.draft:
logger.info('Using abundance file:%s' % args.abundance_file)
abundance_dic = abundance.parse_abundance_file(args.abundance_file)
elif args.coverage and not args.draft:
logger.warning('--coverage is an experimental feature')
logger.info('Using coverage file:%s' % args.coverage)
abundance_dic = abundance.parse_abundance_file(args.coverage)
elif args.abundance in abundance_dispatch:
logger.info('Using %s abundance distribution' % args.abundance)
if args.draft:
abundance_dic = abundance.draft(
genome_list, args.draft,
abundance_dispatch[args.abundance], args.output)
else:
abundance_dic = abundance_dispatch[args.abundance](genome_list)
abundance.to_file(abundance_dic, args.output)
else:
logger.error('Could not get abundance')
sys.exit(1)
cpus = args.cpus
logger.info('Using %s cpus for read generation' % cpus)
if not args.coverage:
n_reads = util.convert_n_reads(args.n_reads)
logger.info('Generating %s reads' % n_reads)
try:
temp_file_list = [] # list holding the prefix of all temp files
f = open(genome_file, 'r') # re-opens the file
with f:
fasta_file = SeqIO.parse(f, 'fasta')
for record in fasta_file:
# generate reads for records
try:
species_abundance = abundance_dic[record.id]
except KeyError as e:
logger.error(
'Fasta record not found in abundance file: %s' % e)
sys.exit(1)
else:
logger.info('Generating reads for record: %s' %
record.id)
genome_size = len(record.seq)
if args.coverage:
coverage = species_abundance
else:
coverage = abundance.to_coverage(
n_reads, species_abundance,
err_mod.read_length, genome_size)
n_pairs = int(
round((coverage * len(record.seq)) /
err_mod.read_length) / 2)
# skip record if n_reads == 0
if n_pairs == 0:
continue
# exact n_reads for each cpus
if n_pairs % cpus == 0:
n_pairs_per_cpu = [(n_pairs // cpus)
for _ in range(cpus)]
else:
n_pairs_per_cpu = [(n_pairs // cpus)
for _ in range(cpus)]
n_pairs_per_cpu[-1] += n_pairs % cpus
# due to a bug in multiprocessing
# https://bugs.python.org/issue17560
# we can't send records taking more than 2**31 bytes
# through serialisation.
# In those cases we use memmapping
if sys.getsizeof(str(record.seq)) >= 2**31 - 1:
logger.warning("record %s unusually big." %
record.id)
logger.warning("Using a memory map.")
mode = "memmap"
record_mmap = "%s.memmap" % args.output
if os.path.exists(record_mmap):
os.unlink(record_mmap)
util.dump(record, record_mmap)
del record
record = record_mmap
gc.collect()
else:
mode = "default"
record_file_name_list = Parallel(n_jobs=cpus)(
delayed(generator.reads)(
record, err_mod, n_pairs_per_cpu[i], i,
args.output, args.seed, args.gc_bias, mode)
for i in range(cpus))
temp_file_list.extend(record_file_name_list)
except KeyboardInterrupt as e:
logger.error('iss generate interrupted: %s' % e)
temp_file_unique = list(set(temp_file_list))
temp_R1 = [temp_file + '_R1.fastq' for temp_file in temp_file_list]
temp_R2 = [temp_file + '_R2.fastq' for temp_file in temp_file_list]
full_tmp_list = temp_R1 + temp_R2
full_tmp_list.append(genome_file)
if os.path.exists("%s.memmap" % args.output):
full_tmp_list.append("%s.memmap" % args.output)
util.cleanup(full_tmp_list)
sys.exit(1)
else:
# remove the duplicates in file list and cleanup
# we remove the duplicates in case two records had the same header
# and reads were appended to the same temp file.
temp_file_unique = list(set(temp_file_list))
temp_R1 = [temp_file + '_R1.fastq' for temp_file in temp_file_list]
temp_R2 = [temp_file + '_R2.fastq' for temp_file in temp_file_list]
util.concatenate(temp_R1, args.output + '_R1.fastq')
util.concatenate(temp_R2, args.output + '_R2.fastq')
full_tmp_list = temp_R1 + temp_R2
full_tmp_list.append(genome_file)
if os.path.exists("%s.memmap" % args.output):
full_tmp_list.append("%s.memmap" % args.output)
util.cleanup(full_tmp_list)
if args.compress:
util.compress(args.output + '_R1.fastq')
util.compress(args.output + '_R2.fastq')
logger.info('Read generation complete')
def generate_reads(args):
"""Main function for the `iss generate` submodule
This submodule generates reads from an ErrorModel and write them to
args.output + _R(1|2).fastq
Args:
args (object): the command-line arguments from argparse
"""
logger = logging.getLogger(__name__)
logger.debug('iss version %s' % __version__)
logger.debug('Using verbose logger')
try: # try to import and load the correct error model
logger.info('Starting iss generate')
logger.info('Using %s ErrorModel' % args.mode)
if args.mode == 'kde':
from iss.error_models import kde
if args.model.lower() == 'hiseq':
npz = os.path.join(os.path.dirname(__file__), 'profiles/HiSeq')
elif args.model.lower() == 'novaseq':
npz = os.path.join(os.path.dirname(__file__),
'profiles/NovaSeq')
elif args.model.lower() == 'miseq':
npz = os.path.join(os.path.dirname(__file__), 'profiles/MiSeq')
elif args.model is None:
logger.error('--model is required in --mode kde')
sys.exit(1)
else:
npz = args.model
err_mod = kde.KDErrorModel(npz)
elif args.mode == 'basic':
if args.model is not None:
logger.warning('--model %s will be ignored in --mode %s' %
(args.model, args.mode))
from iss.error_models import basic
err_mod = basic.BasicErrorModel()
except ImportError as e:
logger.error('Failed to import ErrorModel module: %s' % e)
sys.exit(1)
try: # try to read genomes and generate reads
if args.genomes:
genome_file = args.genomes
elif args.ncbi and args.n_genomes:
util.genome_file_exists(args.output + '_genomes.fasta')
total_genomes = []
try:
assert len(*args.ncbi) == len(*args.n_genomes)
except AssertionError as e:
logger.error(
'--ncbi and --n_genomes of unequal lengths. Aborting')
sys.exit(1)
# for g, n in zip(*args.ncbi, *args.n_genomes): # this is py3 only
# py2 compatibilty workaround
# TODO remove when we drop python2
args.ncbi = [x for y in args.ncbi for x in y]
args.n_genomes = [x for y in args.n_genomes for x in y]
for g, n in zip(args.ncbi, args.n_genomes):
genomes = download.ncbi(g, n)
total_genomes.extend(genomes)
genome_file = download.to_fasta(total_genomes, args.output)
else:
logger.error('Invalid input') # TODO better error handling here
sys.exit(1)
assert os.stat(genome_file).st_size != 0
f = open(genome_file, 'r')
with f: # count the number of records
record_list = util.count_records(f)
except IOError as e:
logger.error('Failed to open genome(s) file:%s' % e)
sys.exit(1)
except AssertionError as e:
logger.error('Genome(s) file seems empty: %s' % genome_file)
sys.exit(1)
except KeyboardInterrupt as e:
logger.error('iss generate interrupted: %s' % e)
sys.exit(1)
else:
abundance_dispatch = {
'uniform': abundance.uniform,
'halfnormal': abundance.halfnormal,
'exponential': abundance.exponential,
'lognormal': abundance.lognormal,
'zero_inflated_lognormal': abundance.zero_inflated_lognormal
}
# read the abundance file
if args.abundance_file:
logger.info('Using abundance file:%s' % args.abundance_file)
abundance_dic = abundance.parse_abundance_file(args.abundance_file)
elif args.abundance in abundance_dispatch:
logger.info('Using %s abundance distribution' % args.abundance)
abundance_dic = abundance_dispatch[args.abundance](record_list)
abundance.to_file(abundance_dic, args.output)
else:
logger.error('Could not get abundance')
sys.exit(1)
cpus = args.cpus
logger.info('Using %s cpus for read generation' % cpus)
n_reads = util.convert_n_reads(args.n_reads)
logger.info('Generating %s reads' % n_reads)
try:
temp_file_list = [] # list holding the prefix of all temp files
f = open(genome_file, 'r') # re-opens the file
with f:
fasta_file = SeqIO.parse(f, 'fasta')
for record in fasta_file: # generate reads for each record
try:
species_abundance = abundance_dic[record.id]
except KeyError as e:
logger.error(
'Fasta record not found in abundance file: %s' % e)
sys.exit(1)
else:
logger.info('Generating reads for record: %s' %
record.id)
genome_size = len(record.seq)
coverage = abundance.to_coverage(
n_reads, species_abundance, err_mod.read_length,
genome_size)
n_pairs = int(
round((coverage * len(record.seq)) /
err_mod.read_length) / 2)
# good enough approximation
n_pairs_per_cpu = int(round(n_pairs / cpus))
record_file_name_list = Parallel(n_jobs=cpus)(
delayed(generator.reads)
(record, err_mod, n_pairs_per_cpu, i, args.output,
args.gc_bias) for i in range(cpus))
temp_file_list.extend(record_file_name_list)
except KeyboardInterrupt as e:
logger.error('iss generate interrupted: %s' % e)
generator.cleanup(temp_file_list)
sys.exit(1)
else:
# remove the duplicates in file list and cleanup
# we remove the duplicates in case two records had the same header
# and reads were appended to the same temp file.
temp_file_unique = list(set(temp_file_list))
generator.concatenate(temp_file_unique, args.output)
generator.cleanup(temp_file_unique)
logger.info('Read generation complete')