def test_read_write_kmers(self):
""" test read/write kmers """
sequence = "ACTGGGTATCGATGACGTATATGCATTGAGAGTACGTATGNNNACTG"
kcounter = Kmer.KmerCounter(2)
kcomparer = Kmer.KmerComparer(kcounter)
spectrums = kcomparer.compute_spectrums([sequence,sequence],["A","B"])
spectrums = np.array(spectrums)
fn = os.path.join(self.datadir, "temp.x")
Kmer.write_spectrums(spectrums, fn)
specs = Kmer.read_spectrums(fn)
for i,j in itertools.product(range(specs.shape[0]),range(specs.shape[1])):
self.assertAlmostEqual(specs[i][j],spectrums[i][j], delta=0.005,
msg="Problem reading/writing k-mer spectrums")
os.remove(fn)
def test_L1_distance(self):
""" test the L1 distance function. The same spectrum must given distance 0 """
ks = [2, 3, 4]
for k in ks:
counter = Kmer.KmerCounter(k)
spectrum1 = counter.get_spectrum(self.sequence)
spectrum2 = counter.get_spectrum(self.sequence)
d = Kmer.L1_distance(spectrum1, spectrum2)
expected_distance = 0.0
self.assertAlmostEqual(
d,
expected_distance,
delta=1e-5,
msg="L1 distance: {0}. Expected: {1} k = {2}".format(
d, expected_distance, k))
def test_kmer_counter_whit_unknown2(self):
""" Test counting kmers of size 2 in a sequence that has unknown values
"""
counter = Kmer.KmerCounter(2)
result = counter.count(self.seq_with_unknown)
expected = np.array([1, 1, 1, 2, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0])
self.check(result, expected)
def test_kmer_counter1(self):
""" Test counting kmers of size 1
"""
counter = Kmer.KmerCounter(1)
result = counter.count(self.sequence)
expected = np.array([5, 4, 5, 6])
self.check(result, expected)
def test_kmer_counter2(self):
""" Test counting kmers of size 2
"""
counter = Kmer.KmerCounter(2)
result = counter.count(self.sequence)
expected = np.array([1, 1, 1, 2, 1, 1, 0, 2, 1, 2, 1, 1, 1, 0, 3, 1])
self.check(result, expected)
def add_scaffold_spectrums(self, kmer_size):
""" Calculate the k-mer spectrums for the scaffolds
The sequences of the scaffolds are read from the database and
their spectrums are stored as a new column
@param k The size of the kmers
"""
log.debug(
"Adding a column with the k-mer spectrums to the scaffolds table")
if not self.table_exists(self.ScaffoldsTable):
raise ValueError(
"Cannot add k-mer spectrums. Scaffolds table does not exist")
if not "spectrum" in self.get_table_column_names(self.ScaffoldsTable):
self.add_column(self.ScaffoldsTable, "spectrum", str)
kcounter = Kmer.KmerCounter(kmer_size)
kcomparer = Kmer.KmerComparer(kcounter)
sql_command = """SELECT scaffold, sequence FROM {0}""".format(
self.ScaffoldsTable)
cursor = self.execute(sql_command)
record = cursor.fetchone()
batch_size = 1000
sequences = []
scaffolds = []
update_command = """ UPDATE {0} SET spectrum=? WHERE scaffold=? """.format(
self.ScaffoldsTable)
while record:
scaffold = record["scaffold"]
scaffolds.append(scaffold)
sequences.append(record["sequence"])
if len(sequences) == batch_size:
spectrums = kcomparer.compute_spectrums(sequences, scaffolds)
data = [("#".join(map(str, sp)), sc)
for sp, sc in zip(spectrums, scaffolds)]
self.executemany(update_command, data)
self.commit()
sequences = []
scaffolds = []
record = cursor.fetchone()
if len(sequences) > 0:
spectrums = kcomparer.compute_spectrums(sequences, scaffolds)
data = [("#".join(map(str, sp)), sc)
for sp, sc in zip(spectrums, scaffolds)]
self.executemany(update_command, data)
self.commit()
sequences = []
scaffolds = []
def test_read_write_kmers(self):
""" test read/write kmers """
sequence = "ACTGGGTATCGATGACGTATATGCATTGAGAGTACGTATGNNNACTG"
kcounter = Kmer.KmerCounter(2)
kcomparer = Kmer.KmerComparer(kcounter)
spectrums = kcomparer.compute_spectrums([sequence, sequence],
["A", "B"])
spectrums = np.array(spectrums)
fn = os.path.join(self.datadir, "temp.x")
Kmer.write_spectrums(spectrums, fn)
specs = Kmer.read_spectrums(fn)
for i, j in itertools.product(range(specs.shape[0]),
range(specs.shape[1])):
self.assertAlmostEqual(
specs[i][j],
spectrums[i][j],
delta=0.005,
msg="Problem reading/writing k-mer spectrums")
os.remove(fn)
def do_kmer_comparison(args):
""" Compares the Kmer spectrums.
Compares the scaffolds assigned using blast with the not assigned
scaffolds
"""
log.info("Performing kmer comparison. Parameters: ")
log.info("kmer size: %s dist12: %s threshold: %s", args.kmer,
args.dist12,args.threshold)
db = MetagenomeDatabase.MetagenomeDatabase(args.fn_database)
kcounter = Kmer.KmerCounter(args.kmer)
kcomparer = Kmer.KmerComparer(kcounter)
kcomparer.set_kmer_distance_threshold(args.threshold)
kcomparer.set_first_to_second_distance_ratio(args.dist12)
# add the combined sequences of the scaffolds belonging to the same genera
genus2sequence_dict, assigned_scaffolds = \
db.get_genera_sequences_from(db.ScaffoldKmerComparisonTable)
for genus in genus2sequence_dict:
kcomparer.add_reference_sequence(genus2sequence_dict[genus],genus)
sql_command = "SELECT scaffold, sequence FROM {0}".format(db.ScaffoldsTable)
cursor = db.execute(sql_command)
batch_size = 1000
all_assignments = []
record = cursor.fetchone()
while record:
scaffold = record["scaffold"]
if scaffold not in assigned_scaffolds:
kcomparer.add_sequence(record["sequence"], scaffold)
if kcomparer.get_number_of_sequences() == batch_size:
matches = kcomparer.run()
all_assignments.extend(matches)
record = cursor.fetchone()
if kcomparer.get_number_of_sequences() > 0:
matches = kcomparer.run()
all_assignments.extend(matches)
db.store_data(db.ScaffoldKmerComparisonTable, all_assignments)
db.close()
def kmer_comparison_one_iteration(args):
""" This function is the one-iteration version of the iterative function
"""
db = MetagenomeDatabase.MetagenomeDatabase(args.fn_database)
names = db.get_tables_names()
if db.ScaffoldKmerComparisonTable in names:
db.drop_table(db.ScaffoldKmerComparisonTable)
db.create_scaffold_kmer_comparison_table()
kcounter = Kmer.KmerCounter(args.kmer)
kcomparer = Kmer.KmerComparer(kcounter)
kcomparer.set_kmer_distance_threshold(args.threshold)
kcomparer.set_first_to_second_distance_ratio(args.dist12)
# add the combined sequences of the scaffolds belonging to the same genera
genus2sequence_dict, assigned_scaffolds = db.get_genera_sequences_from(db.ScaffoldsAssignmentsTable)
for genus in genus2sequence_dict:
kcomparer.add_reference_sequence(genus2sequence_dict[genus],genus)
sql_command = "SELECT scaffold, sequence FROM {0}".format(db.ScaffoldsTable)
cursor = db.execute(sql_command)
batch_size = 1000
all_matches = []
record = cursor.fetchone()
while record:
scaffold = record["scaffold"]
if scaffold not in assigned_scaffolds:
kcomparer.add_sequence(record["sequence"], scaffold)
if kcomparer.get_number_of_sequences() == batch_size:
matches = kcomparer.run()
# kcomparer will return False if a reliable match has not been found
all_matches.extend([m for m in matches if m[1] != False])
record = cursor.fetchone()
if kcomparer.get_number_of_sequences() > 0:
matches = kcomparer.run()
all_matches.extend([m for m in matches if m[1] != False])
db.store_data(db.ScaffoldKmerComparisonTable, all_matches)
db.close()
def test_spectrum_of_unique_kmers(self):
""" Test the spectrums of unique kmers """
fn = os.path.join(self.datadir, "thermus.fasta")
f = open(fn, 'r')
f.readline() # discard first line (header)
sequence = f.readline()
f.close()
for kmersize in [2, 3, 4]:
kmercounter = Kmer.KmerCounter(kmersize)
spectrum = kmercounter.get_spectrum(sequence)
uspectrum = kmercounter.get_unique_kmers_spectrum(sequence)
self.assertGreater(len(spectrum), len(uspectrum))
self.assertAlmostEqual(spectrum.sum(),
1,
delta=0.001,
msg="problem with spectrum")
self.assertAlmostEqual(uspectrum.sum(),
1,
delta=0.001,
msg="problem with spectrum of unique kmers")
counts = kmercounter.count(sequence)
ucounts = kmercounter.get_unique_kmers_counts(sequence)
self.assertEqual(counts.sum(), ucounts.sum(),
"The kmer counts must be the same")
logging.root.setLevel(logging.DEBUG)
"""
This script shows how to calculate the spectrum of a DNA sequence
"""
# read the DNA
f = open('thermus.fasta', 'r')
f.readline() # discard first line (header)
sequence = f.readline()
f.close()
kmersize = 4
alphabet = "ACGT"
kmers = Kmer.generate_kmers(kmersize, alphabet)
print "The kmers are "
print kmers
kmers = Kmer.remove_reversed(kmers)
print "the", len(kmers), "unique kmers are", kmers
kmercounter = Kmer.KmerCounter(kmersize)
kmercounter.set_alphabet(alphabet)
spectrum = kmercounter.get_spectrum(sequence)
print "The length of the kmer spectrum is", kmercounter.get_spectrum_length()
print "And the spectrum is:"
print spectrum
spectrum = kmercounter.get_unique_kmers_spectrum(sequence)
print "The length of the spectrum of unique kmers is", len(spectrum)
"""
This script shows how to calculate the spectrum of a DNA sequence
"""
# read the DNA
f = open("thermus.fasta", "r")
f.readline() # discard first line (header)
sequence = f.readline()
f.close()
kmersize = 4
alphabet = "ACGT"
kmers = Kmer.generate_kmers(kmersize, alphabet)
print "The kmers are "
print kmers
kmers = Kmer.remove_reversed(kmers)
print "the", len(kmers), "unique kmers are", kmers
kmercounter = Kmer.KmerCounter(kmersize)
kmercounter.set_alphabet(alphabet)
spectrum = kmercounter.get_spectrum(sequence)
print "The length of the kmer spectrum is", kmercounter.get_spectrum_length()
print "And the spectrum is:"
print spectrum
