Package cc.mallet.fst

Class CRFOptimizableByBatchLabelLikelihood

java.lang.Object

cc.mallet.fst.CRFOptimizableByBatchLabelLikelihood

All Implemented Interfaces:

Optimizable, Optimizable.ByCombiningBatchGradient, java.io.Serializable

public class CRFOptimizableByBatchLabelLikelihood
extends java.lang.Object
implements Optimizable.ByCombiningBatchGradient, java.io.Serializable

Implements label likelihood gradient computations for batches of data, can be easily parallelized.

The gradient computations are the same as that of CRFOptimizableByLabelLikelihood.

*Note*: Expectations corresponding to each batch of data can be computed in parallel. During gradient computation, the prior and the constraints are incorporated into the expectations of the last batch (see getBatchValue, getBatchValueGradient). *Note*: This implementation ignores instances with infinite weights (see getExpectationValue).

Author:

Gaurav Chandalia

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CRFOptimizableByBatchLabelLikelihood.Factory

Nested classes/interfaces inherited from interface cc.mallet.optimize.Optimizable

Optimizable.ByBatchGradient, Optimizable.ByCombiningBatchGradient, Optimizable.ByGISUpdate, Optimizable.ByGradient, Optimizable.ByGradientValue, Optimizable.ByHessian, Optimizable.ByValue, Optimizable.ByVotedPerceptron

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.List<double[]>	cachedGradient
protected double[]	cachedValue
protected CRF.Factors	constraints
protected CRF	crf
protected java.util.List<CRF.Factors>	expectations
protected int	numBatches
protected InstanceList	trainingSet

Constructor Summary

Constructors

Constructor	Description
CRFOptimizableByBatchLabelLikelihood(CRF crf, InstanceList ilist, int numBatches)

Method Summary

Modifier and Type	Method	Description
void	combineGradients(java.util.Collection<double[]> batchGradients, double[] buffer)	Adds gradients from all batches.
protected void	gatherConstraints(InstanceList ilist)	Set the constraints by running forward-backward with the output label sequence provided, thus restricting it to only those paths that agree with the label sequence.
double	getBatchValue(int batchIndex, int[] batchAssignments)	Returns the log probability of a batch of training sequence labels and the prior over parameters, if last batch then incorporate the prior on parameters as well.
void	getBatchValueGradient(double[] buffer, int batchIndex, int[] batchAssignments)
protected double	getExpectationValue(int batchIndex, int[] batchAssignments)	Computes log probability of a batch of training data, fill in corresponding expectations as well
double	getGaussianPriorVariance()
int	getNumBatches()
int	getNumParameters()
double	getParameter(int index)
void	getParameters(double[] buffer)
double	getUseHyperbolicPriorSharpness()
double	getUseHyperbolicPriorSlope()
void	setGaussianPriorVariance(double p)
void	setHyperbolicPriorSharpness(double p)
void	setHyperbolicPriorSlope(double p)
void	setParameter(int index, double value)
void	setParameters(double[] buff)
void	setUseHyperbolicPrior(boolean f)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

crf

protected CRF crf

trainingSet

protected InstanceList trainingSet

numBatches

protected int numBatches

expectations

protected java.util.List<CRF.Factors> expectations

constraints

protected CRF.Factors constraints

cachedValue

protected double[] cachedValue

cachedGradient

protected java.util.List<double[]> cachedGradient

Constructor Detail

CRFOptimizableByBatchLabelLikelihood

public CRFOptimizableByBatchLabelLikelihood(CRF crf,
                                            InstanceList ilist,
                                            int numBatches)

Method Detail

gatherConstraints

protected void gatherConstraints(InstanceList ilist)

Set the constraints by running forward-backward with the output label sequence provided, thus restricting it to only those paths that agree with the label sequence.

getExpectationValue

protected double getExpectationValue(int batchIndex,
                                     int[] batchAssignments)

Computes log probability of a batch of training data, fill in corresponding expectations as well

getBatchValue

public double getBatchValue(int batchIndex,
                            int[] batchAssignments)

Returns the log probability of a batch of training sequence labels and the prior over parameters, if last batch then incorporate the prior on parameters as well.

Specified by:

getBatchValue in interface Optimizable.ByCombiningBatchGradient

getBatchValueGradient

public void getBatchValueGradient(double[] buffer,
                                  int batchIndex,
                                  int[] batchAssignments)

Specified by:

getBatchValueGradient in interface Optimizable.ByCombiningBatchGradient

combineGradients

public void combineGradients(java.util.Collection<double[]> batchGradients,
                             double[] buffer)

Adds gradients from all batches.

Note: assumes buffer is already initialized.

Specified by:

combineGradients in interface Optimizable.ByCombiningBatchGradient

getNumBatches

public int getNumBatches()

Specified by:

getNumBatches in interface Optimizable.ByCombiningBatchGradient

setUseHyperbolicPrior

public void setUseHyperbolicPrior(boolean f)

setHyperbolicPriorSlope

public void setHyperbolicPriorSlope(double p)

setHyperbolicPriorSharpness

public void setHyperbolicPriorSharpness(double p)

getUseHyperbolicPriorSlope

public double getUseHyperbolicPriorSlope()

getUseHyperbolicPriorSharpness

public double getUseHyperbolicPriorSharpness()

setGaussianPriorVariance

public void setGaussianPriorVariance(double p)

getGaussianPriorVariance

public double getGaussianPriorVariance()

getNumParameters

public int getNumParameters()

Specified by:

getNumParameters in interface Optimizable

getParameters

public void getParameters(double[] buffer)

Specified by:

getParameters in interface Optimizable

getParameter

public double getParameter(int index)

Specified by:

getParameter in interface Optimizable

setParameters

public void setParameters(double[] buff)

Specified by:

setParameters in interface Optimizable

setParameter

public void setParameter(int index,
                         double value)

Specified by:

setParameter in interface Optimizable