snpSelector v1 -- and supporting changes to VCF reader

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@1983 348d0f76-0448-11de-a6fe-93d51630548a
This commit is contained in:
depristo 2009-11-06 23:00:46 +00:00
parent 66d4a995e6
commit 7cb51dbc31
2 changed files with 362 additions and 4 deletions

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@ -0,0 +1,307 @@
import os.path
import sys
from optparse import OptionParser
from vcfReader import *
#import pylab
from itertools import *
import math
class RecalibratedCall:
def __init__(self, call, features):
self.call = call
self.features = dict([[feature, None] for feature in features])
def recalFeature( self, feature, FPRate ):
assert self.features[feature] == None # not reassigning values
assert FPRate <= 1 and FPRate >= 0
self.features[feature] = FPRate
def getFeature( self, feature, missingValue = None, phredScaleValue = False ):
v = self.features[feature]
if v == None:
return missingValue
elif phredScaleValue:
return phredScale(v)
else:
return v
def jointFPErrorRate(self):
#print self.features
logTPRates = [math.log10(1-r) for r in self.features.itervalues() if r <> None]
logJointTPRate = reduce(lambda x, y: x + y, logTPRates, 0)
jointTPRate = math.pow(10, logJointTPRate)
#print logTPRates
#print logJointTPRate, jointTPRate
return 1 - jointTPRate
def featureStringList(self):
return ','.join(map(lambda feature: '%s=Q%d' % (feature, self.getFeature(feature, '*', True)), self.features.iterkeys()))
def __str__(self):
return '[%s: %s => Q%d]' % (str(self.call), self.featureStringList(), phredScale(self.jointFPErrorRate()))
def readVariants( file ):
counter = OPTIONS.skip
def parseVariant(args):
VCF, counter = args
if counter % OPTIONS.skip == 0:
return VCF
else:
return None
return filter(None, map(parseVariant, lines2VCF(open(file))))
def selectVariants( variants, selector = None ):
if selector <> None:
return filter(selector, variants)
else:
return variants
def titv(variants):
ti = len(filter(VCFRecord.isTransition, variants))
tv = len(variants) - ti
titv = ti / (1.0*max(tv,1))
return titv, ti, tv
def gaussian(x, mu, sigma):
constant = 1 / math.sqrt(2 * math.pi * sigma**2)
exponent = -1 * ( x - mu )**2 / (2 * sigma**2)
return constant * math.exp(exponent)
DEBUG = False
# if target = T, and FP calls have ti/tv = 0.5, we want to know how many FP calls
# there are in N calls with ti/tv of X.
#
def titvFPRateEstimate(variants, target):
titvRatio, ti, tv = titv(variants)
# f <- function(To,T) { (To - T) / (1/2 - T) + 0.001 }
def theoreticalCalc():
if titvRatio >= target:
FPRate = 0
else:
FPRate = (titvRatio - target) / (0.5 - target)
FPRate = min(max(FPRate, 0), 1)
TPRate = max(min(1 - FPRate, 1 - dephredScale(OPTIONS.maxQScore)), dephredScale(OPTIONS.maxQScore))
print 'FPRate', FPRate, titvRatio, target
assert FPRate >= 0 and FPRate <= 1
return TPRate
# gaussian model
def gaussianModel():
LEFT_HANDED = True
sigma = 5
constant = 1 / math.sqrt(2 * math.pi * sigma**2)
exponent = -1 * ( titvRatio - target )**2 / (2 * sigma**2)
TPRate = gaussian(titvRatio, target, sigma) / gaussian(target, target, sigma)
if LEFT_HANDED and titvRatio >= target:
TPRate = 1
TPRate -= dephredScale(OPTIONS.maxQScore)
if DEBUG: print 'TPRate', TPRate, constant, exponent, dephredScale(OPTIONS.maxQScore)
return TPRate
#denom = (0.2 - 0.8 * titvRatio)
#FPRate = 1
#if denom <> 0:
# FPRate = (1.0 / (target+1)) * (titvRatio - target) / denom
FPRate = 1 - gaussianModel()
nVariants = len(variants)
if nVariants > 0:
impliedNoErrors = nVariants * FPRate
calcTiTv = (impliedNoErrors * 0.5 + target * (nVariants-impliedNoErrors)) / nVariants
else:
impliedNoErrors, calcTiTv = 0, 0
if DEBUG: print ':::', nVariants, titvRatio, target, ti, tv, FPRate, impliedNoErrors, calcTiTv
return titvRatio, FPRate, impliedNoErrors
def phredScale(errorRate):
return -10 * math.log10(max(errorRate, 1e-10))
def dephredScale(qscore):
return math.pow(10, qscore / -10)
def frange6(*args):
"""A float range generator."""
start = 0.0
step = 1.0
l = len(args)
if l == 1:
end = args[0]
elif l == 2:
start, end = args
elif l == 3:
start, end, step = args
if step == 0.0:
raise ValueError, "step must not be zero"
else:
raise TypeError, "frange expects 1-3 arguments, got %d" % l
v = start
while True:
if (step > 0 and v >= end) or (step < 0 and v <= end):
raise StopIteration
yield v
v += step
def calculateBins(variants, field, minValue, maxValue, rangeValue, partitions):
sortedVariants = sorted(variants, key = lambda x: x.getField(field))
sortedValues = map(lambda x: x.getField(field), sortedVariants)
targetBinSize = len(variants) / (1.0*partitions)
print 'targetBinSize', targetBinSize
uniqBins = groupby(sortedValues)
binsAndSizes = map(lambda x: [x[0], len(list(x[1]))], uniqBins)
#print binsAndSizes
def bin2Break(bin): return [bin[0], bin[0], bin[1]]
bins = [bin2Break(binsAndSizes[0])]
for bin in binsAndSizes[1:]:
#print 'Breaks', bins
curSize = bin[1]
prevSize = bins[-1][2]
if curSize + prevSize > targetBinSize:
bins.append(bin2Break(bin))
else:
bins[-1][1] = bin[0]
bins[-1][2] += curSize
return bins
def calculateBinsLinear(variants, minValue, maxValue, rangeValue, partitions):
breaks = list(frange6(minValue, maxValue, rangeValue / partitions))
if breaks[len(breaks)-1] <> maxValue:
breaks = breaks + ['*']
return zip(breaks, map( lambda x: x - 0.001, breaks[1:]))
def fieldRange(variants, field):
values = map(lambda v: v.getField(field), variants)
minValue = min(values)
maxValue = max(values)
rangeValue = maxValue - minValue
bins = calculateBins(variants, field, minValue, maxValue, rangeValue, OPTIONS.partitions)
return minValue, maxValue, rangeValue, bins
def printFieldQual( left, right, variants, titv, FPRate, nErrors ):
leftStr = str(left)
if type(left) == float: leftStr = "%.2f" % left
rightStr = "%5s" % str(right)
if type(right) == float: rightStr = "%.2f" % right
#print 'FPRATe', FPRate, phredScale(FPRate)
print ' %8s - %8s nVariants=%8d titv=%.2f FPRate=%.2e Q%d' % (leftStr, rightStr, len(variants), titv, FPRate, phredScale(FPRate))
#
#
#
def optimizeCalls(variants, fields, titvTarget):
recalCalls = calibrateFeatures(variants, fields, titvTarget)
newCalls = list()
for recalCall in recalCalls.itervalues():
originalQual = recalCall.call.getField('QUAL')
recalCall.call.setField('QUAL', int(round(phredScale(recalCall.jointFPErrorRate()))))
recalCall.call.setField('OQ', originalQual)
newCalls.append(recalCall.call)
for recalCall in islice(recalCalls.itervalues(), 10):
print recalCall
print '--------------------------------------------------------------------------------'
print 'RECALIBRATED CALLS'
#newCalls = [x.call for x in recalCalls.itervalues()]
calibrateFeatures(newCalls, ['QUAL'], titvTarget, updateCalls = False, printCall = True )
return newCalls
def all( p, l ):
for elt in l:
if not p(elt): return False
return True
def calibrateFeatures(variants, fields, titvTarget, updateCalls = True, printCall = False):
if updateCalls: recalCalls = dict([[variant, RecalibratedCall(variant, fields)] for variant in variants])
for field in fields:
print 'Optimizing field', field
if not all( lambda x: x.hasField(field), variants):
raise Exception('Unknown field ' + field)
minValue, maxValue, range, bins = fieldRange(variants, field)
print 'Field range', minValue, maxValue, range
print 'Partitions', bins
titv, FPRate, nErrors = titvFPRateEstimate(variants, titvTarget)
print 'Overall FRRate:', FPRate, nErrors, phredScale(FPRate)
for left, right in map(lambda x: [x[0], x[1]], bins):
#print 'LR:', left, right
def select( variant ): return variant.getField(field) >= left and (right == '*' or variant.getField(field) <= right)
selectedVariants = selectVariants(variants, select)
if len(selectedVariants) > max(OPTIONS.minVariantsPerBin,1):
titv, FPRate, nErrors = titvFPRateEstimate(selectedVariants, titvTarget)
if updateCalls:
for variant in selectedVariants: recalCalls[variant].recalFeature(field, FPRate)
if printCall:
for call in selectedVariants:
if titv < 0.5:
print call
printFieldQual( left, right, selectedVariants, titv, FPRate, nErrors )
if updateCalls:
return recalCalls
else:
return None
def main():
global OPTIONS
usage = "usage: %prog files.list [options]"
parser = OptionParser(usage=usage)
parser.add_option("-f", "--f", dest="fields",
type='string', default="QUAL",
help="Comma-separated list of fields to exact")
parser.add_option("-t", "--truth", dest="truth",
type='string', default=None,
help="VCF formated truth file")
parser.add_option("-p", "--partitions", dest="partitions",
type='int', default=10,
help="Number of partitions to examine")
parser.add_option("-s", "--s", dest="skip",
type='int', default=1,
help="Only work with every 1 / skip records")
parser.add_option("-m", "--minVariantsPerBin", dest="minVariantsPerBin",
type='int', default=10,
help="")
parser.add_option("-q", "--qMax", dest="maxQScore",
type='int', default=30,
help="")
parser.add_option("", "--titv", dest="titvTarget",
type='float', default=None,
help="If provided, we will optimize calls to the targeted ti/tv rather than that calculated from known calls")
(OPTIONS, args) = parser.parse_args()
if len(args) != 2:
parser.error("incorrect number of arguments")
fields = OPTIONS.fields.split(',')
calls = readVariants(args[0])
print 'Read', len(calls), 'calls'
if OPTIONS.titvTarget == None:
OPTIONS.titvTarget = titv(calls, VCFRecord.isKnown)
print 'Ti/Tv all ', titv(calls)
print 'Ti/Tv known', titv(selectVariants(calls, VCFRecord.isKnown))
print 'Ti/Tv novel', titv(selectVariants(calls, VCFRecord.isNovel))
optimizeCalls(calls, OPTIONS.fields.split(","), OPTIONS.titvTarget)
if __name__ == "__main__":
main()

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@ -1,9 +1,28 @@
TRANSITIONS = dict()
for p in ["AG", "CT"]:
TRANSITIONS[p] = True
TRANSITIONS[''.join(reversed(p))] = True
def convertToType(d):
out = dict()
types = [int, float, str]
for key, value in d.items():
for type in types:
try:
#print 'Parsing', key, value, type
out[key] = type(value)
#print ' Parsed as', key, value, type
break
except:
pass
return out
class VCFRecord:
"""Simple support for accessing a VCF record"""
def __init__(self, basicBindings, header=None):
self.header = header
self.bindings = basicBindings
self.info = parseInfo(basicBindings["INFO"])
self.info = convertToType(parseInfo(basicBindings["INFO"]))
self.bindings = convertToType(basicBindings)
def hasHeader(self): return self.header <> None
def getHeader(self): return self.header
@ -21,11 +40,34 @@ class VCFRecord:
def getAlt(self): return self.get("ALT")
def getQual(self): return self.get("QUAL")
def getVariation(self): return self.getRef() + self.getAlt()
def isTransition(self):
#print self.getVariation(), TRANSITIONS
return self.getVariation() in TRANSITIONS
def isTransversion(self):
return not self.isTransition()
def getFilter(self): return self.get("FILTER")
def failsFilters(self): return not self.passesFilters()
def passesFilters(self):
#print self.getFilter(), ">>>", self
return self.getFilter() == "." or self.getFilter() == "0"
def hasField(self, field):
return field in self.bindings or field in self.info
def setField(self, field, value):
assert value <> None
#print 'setting field', field, value
#print 'getInfo', self.getInfo()
if field in self.bindings:
self.bindings[field] = value
else:
self.info[field] = value
self.setField("INFO", self.getInfo())
#print 'getInfo', self.getInfo()
def getField(self, field, default = None):
if field in self.bindings:
@ -35,7 +77,15 @@ class VCFRecord:
else:
return default
def getInfo(self): return self.get("INFO")
#def getInfo(self): return self.get("INFO")
def getInfo(self):
def info2str(x,y):
if type(y) == bool:
return str(x)
else:
return str(x) + '=' + str(y)
return ';'.join(map(lambda x: info2str(*x), self.info.iteritems()))
def getInfoDict(self): return self.info
def getInfoKey(self, name, default = None):
@ -49,7 +99,8 @@ class VCFRecord:
return all(map(lambda key: key in self.getInfo(), keys))
def __str__(self):
return str(self.bindings) + " INFO: " + str(self.info)
#return str(self.bindings) + " INFO: " + str(self.info)
return ' '.join(['%s=%s' % (x,y) for x,y in self.bindings.iteritems()])
def parseInfo(s):
def handleBoolean(key_val):