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#!/usr/bin/python
import os
import sys
import scipy.optimize.nnls
import scipy.sparse
import numpy as np
import quikr_util as qu
from subprocess import *
import argparse
import platform
import gzip
import itertools
def generate_kmers(kmer):
""" This will return a list of kmers seperated by newlines """
return '\n'.join(''.join(x) for x in itertools.product('acgt', repeat=kmer))
def isCompressed(filename):
""" This function checks to see if the file is gzipped """
f = open(filename, "rb")
# The first two bytes of a gzipped file are always '1f 8b'
if f.read(2) == '\x1f\x8b':
f.close()
return True
else:
f.close()
return False
def quikr_train(input_file_location, kmer):
"""
Takes a input fasta file, and kmer, returns a custom trained matrix
"""
kmer_file_name = str(kmer) + "mers.txt"
if not os.path.isfile(kmer_file_name):
print "could not find kmer file"
exit()
uname = platform.uname()[0]
if uname == "Linux":
input_file = Popen(["./probabilities-by-read-linux", str(kmer), input_file_location, kmer_file_name], stdout=PIPE)
elif uname == "Darwin":
input_file = Popen(["./probabilities-by-read-osx", str(kmer), input_file_location, kmer_file_name])
# load and normalize the matrix by dividing each element by the sum of it's column.
# also do some fancy rotations so that it works properly with quikr
matrix = np.loadtxt(input_file.stdout)
matrix = np.rot90(matrix)
matrix = matrix / matrix.sum(0)
matrix = np.flipud(matrix);
return matrix
def quikr_load_trained_matrix_from_file(input_fasta_location, trained_matrix_location, kmer, default_lambda):
""" This is a helper function to load our trained matrix and run quikr """
if qu.isCompressed(trained_matrix_location):
trained_matrix_file = gzip.open(trained_matrix_location, "rb")
else:
trained_matrix_file = open(trained_matrix_location, "rb")
trained_matrix = np.load(trained_matrix_file)
xstar = quikr(input_fasta_location, trained_matrix, kmer, default_lambda)
return xstar
def quikr(input_fasta_location, trained_matrix, kmer, default_lambda):
"""
input_fasta is the input fasta file to find the estimated frequencies of
trained_matrix is the trained matrix we are using to estimate the species
kmer is the desired k-mer to use
default_lambda is inp
returns the estimated requencies of bacteria present when given an input
FASTA file of amplicon (454) reads. A k-mer based, L1 regularized, sparsity
promoting algorthim is utilized.
In practice reconstruction is accurate only down to the genus level (not
species or strain).
"""
uname = platform.uname()[0]
# We use the count program to count ____
if uname == "Linux" and os.path.isfile("./count-linux"):
count_input = Popen(["./count-linux", "-r", str(kmer), "-1", "-u", input_fasta_location], stdout=PIPE)
elif uname == "Darwin" and os.path.isfile("./count-osx"):
count_input = Popen(["count-osx", "-r", str(kmer), "-1", "-u", input_fasta_location], stdout=PIPE)
# load the output of our count program and form a probability vector from the counts
counts = np.loadtxt(count_input.stdout)
counts = counts / counts.sum(0)
counts = default_lambda * counts
counts = np.concatenate([np.zeros(1), counts])
#form the k-mer sensing matrix
trained_matrix = trained_matrix * default_lambda;
trained_matrix = np.vstack((np.ones(trained_matrix.shape[1]), trained_matrix))
xstar, rnorm = scipy.optimize.nnls(trained_matrix, counts)
xstar = xstar / xstar.sum(0)
return xstar
if __name__ == "__main__":
sys.exit(main())
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