def recordDefaults(learner,gradAccum,Y,P,**kw):
"""A default status message."""
gradAccum.counter['n'] = mutil.numRows(Y)
Tracer._record(gradAccum,
Tracer.identification(learner,kw)
+ Tracer.loss(learner,Y,P,kw)
+ Tracer.timing(learner,kw))
def defaultPlusAcc(learner,gradAccum,Y,P,**kw):
"""A default status message."""
gradAccum.counter['n'] = mutil.numRows(Y)
Tracer._announce(gradAccum,
Tracer.identification(learner,kw)
+ Tracer.loss(learner,Y,P,kw)
+ Tracer.accuracy(learner,Y,P,kw)
+ Tracer.timing(learner,kw))
def shuffle(self):
for mode in self.xDict:
shuffledRowNums = NP.arange(mutil.numRows(self.xDict[mode]))
NR.shuffle(shuffledRowNums)
self.xDict[mode] = mutil.shuffleRows(self.xDict[mode],
shuffledRowNums)
self.yDict[mode] = mutil.shuffleRows(self.yDict[mode],
shuffledRowNums)
def train(self,mode,X,Y):
trainStartTime = time.time()
for i in range(self.epochs):
startTime = time.time()
n = mutil.numRows(X)
args = {'i':i,'startTime':startTime}
paramGrads = self.crossEntropyGrad(mode,X,Y,tracerArgs=args)
self.regularizer.regularizeParams(self.prog,n)
self.applyUpdate(paramGrads,self.rate)
def datasetCrossEntropy(goldDset,predictedDset,perExample=True):
""" Return cross entropy on a dataset. """
result = 0.0
for mode in goldDset.modesToLearn():
assert predictedDset.hasMode(mode), "CrossEntropy: Mode '%s' not available in predictedDset" % mode
Y = goldDset.getY(mode)
P = predictedDset.getY(mode)
divisor = mutil.numRows(Y) if perExample else 1.0
result += Learner.crossEntropy(Y,P,perExample=False)/divisor
return result
def datasetAccuracy(goldDset,predictedDset):
""" Return accuracy on a dataset relative to gold labels. """
weightedSum = 0.0
totalWeight = 0.0
for mode in goldDset.modesToLearn():
assert predictedDset.hasMode(mode), "Accuracy: Mode '%s' not available in predictedDset" % mode
Y = goldDset.getY(mode)
P = predictedDset.getY(mode)
weight = mutil.numRows(Y)
weightedSum += weight * Learner.accuracy(Y,P)
totalWeight += weight
if totalWeight == 0: return 0
return weightedSum/totalWeight
def accuracy(Y,P):
"""Evaluate accuracy of predictions P versus labels Y."""
#TODO surely there's a better way of doing this
def allZerosButArgmax(d):
result = NP.zeros_like(d)
result[d.argmax()] = 1.0
return result
n = mutil.numRows(P)
ok = 0.0
for i in range(n):
pi = P.getrow(i)
yi = Y.getrow(i)
ti = mutil.mapData(allZerosButArgmax,pi)
ok += yi.multiply(ti).sum()
return ok/n
def train(self,dset):
trainStartTime = time.time()
modes = dset.modesToLearn()
numModes = len(modes)
for i in range(self.epochs):
startTime = time.time()
epochCounter = GradAccumulator.counter()
for j,mode in enumerate(dset.modesToLearn()):
n = mutil.numRows(dset.getX(mode))
args = {'i':i,'startTime':startTime,'mode':str(mode)}
try:
paramGrads = self.crossEntropyGrad(mode,dset.getX(mode),dset.getY(mode),tracerArgs=args)
self.regularizer.regularizeParams(self.prog,n)
self.applyUpdate(paramGrads,self.rate)
GradAccumulator.accumToCounter(epochCounter,paramGrads.counter)
except:
print "Unexpected error at %s:" % str(args), sys.exc_info()[:2]
raise
self.epochTracer(self,epochCounter,i=i,startTime=trainStartTime)
def train(self,dset):
trainStartTime = time.time()
modes = dset.modesToLearn()
n = len(modes)
for i in range(self.epochs):
startTime = time.time()
epochCounter = GradAccumulator.counter()
k = 0
for (mode,X,Y) in dset.minibatchIterator(batchSize=self.miniBatchSize):
n = mutil.numRows(X)
k = k+1
args = {'i':i,'k':k,'startTime':startTime,'mode':mode}
try:
paramGrads = self.crossEntropyGrad(mode,X,Y,tracerArgs=args)
self.regularizer.regularizeParams(self.prog,n)
self.applyUpdate(paramGrads,self.rate)
GradAccumulator.accumToCounter(epochCounter,paramGrads.counter)
except:
print "Unexpected error at %s:" % str(args), sys.exc_info()[:2]
raise
self.epochTracer(self,epochCounter,i=i,startTime=trainStartTime)
def minibatchIterator(self, batchSize=100, shuffleFirst=True):
"""Iterate over triples (mode,X',Y') where X' and Y' are sets of
batchSize rows from the full data for mode, randomly selected
(without replacement) from the dataset."""
# randomize the order of the examples
if shuffleFirst: self.shuffle()
# then sample an ordering of the modes
modeList = self.modesToLearn()
modeSampleDict = {}
for modeIndex, mode in enumerate(modeList):
numBatches = int(
math.ceil(mutil.numRows(self.getX(mode)) / float(batchSize)))
modeSampleDict[mode] = NP.ones(numBatches, dtype='int') * modeIndex
modeSamples = NP.concatenate(modeSampleDict.values())
NR.shuffle(modeSamples)
# finally produce the minibatches
currentOffset = [0] * len(modeList)
for modeIndex in modeSamples:
mode = modeList[modeIndex]
lo = currentOffset[modeIndex]
bX = mutil.selectRows(self.getX(mode), lo, lo + batchSize)
bY = mutil.selectRows(self.getY(mode), lo, lo + batchSize)
currentOffset[modeIndex] += batchSize
yield mode, bX, bY
def crossEntropy(Y,P,perExample=False):
"""Compute cross entropy some predications relative to some labels."""
logP = mutil.mapData(NP.log,P)
result = -(Y.multiply(logP).sum())
return result/mutil.numRows(Y) if perExample else result
def cheap(learner,gradAccum,Y,P,**kw):
"""Easy-to-compute status message."""
gradAccum.counter['n'] = mutil.numRows(Y)
Tracer._announce(gradAccum,
Tracer.identification(learner,kw)
+ Tracer.timing(learner,kw))
def silent(learner,gradAccum,Y,P,**kw):
"""No output."""
gradAccum.counter['n'] = mutil.numRows(Y)
pass
def _doBackpropTask(task):
""" Use the workerLearner
"""
(mode, X, Y, args) = task
paramGrads = workerLearner.crossEntropyGrad(mode, X, Y, tracerArgs=args)
return (mutil.numRows(X), paramGrads)
def totalNumExamples(self, miniBatches):
"""The total nummber of examples in all the miniBatches"""
return sum(mutil.numRows(X) for (mode, X, Y) in miniBatches)
def _doEval(self, db, values, pad):
return db.zeros(mutil.numRows(values[0]), self.outputType)
