Package opennlp.tools.ml.perceptron

Class PerceptronModel

java.lang.Object

opennlp.tools.ml.model.AbstractModel

opennlp.tools.ml.perceptron.PerceptronModel

All Implemented Interfaces:

MaxentModel

public class PerceptronModel
extends AbstractModel

A model implementation based one the perceptron algorithm.

Each outcome is represented as a binary perceptron classifier. This supports standard (integer) weighting as well average weighting as described in: Discriminative Training Methods for Hidden Markov Models: Theory and Experiments with the Perceptron Algorithm. Michael Collins, EMNLP 2002.

Nested Class Summary

Nested classes/interfaces inherited from class opennlp.tools.ml.model.AbstractModel

AbstractModel.ModelType

Constructor Summary

Constructors

Constructor	Description
PerceptronModel(Context[] params, String[] predLabels, String[] outcomeNames)	Initializes a PerceptronModel.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)
static double[]	eval(int[] context, double[] prior, EvalParameters model)	Evaluates a PerceptronModel.
double[]	eval(String[] context)	Evaluates a context.
double[]	eval(String[] context, double[] probs)	Evaluates a context.
double[]	eval(String[] context, float[] values)	Evaluates a context with the specified context values.
double[]	eval(String[] context, float[] values, double[] outsums)
int	hashCode()

Methods inherited from class opennlp.tools.ml.model.AbstractModel

getAllOutcomes, getBestOutcome, getDataStructures, getIndex, getModelType, getNumOutcomes, getOutcome

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PerceptronModel

public PerceptronModel(Context[] params,
 String[] predLabels,
 String[] outcomeNames)

Initializes a PerceptronModel.

Parameters:

params - The parameters to set.

predLabels - The predicted labels.

outcomeNames - The names of the outcomes.

Method Details

eval

public double[] eval(String[] context)

Evaluates a context.

Parameters:

context - An array of String names of the contextual predicates which are to be evaluated together.

Returns:

An array of the probabilities for each of the different outcomes, all of which sum to 1.

eval

public double[] eval(String[] context,
 float[] values)

Evaluates a context with the specified context values.

Parameters:

context - An array of String names of the contextual predicates which are to be evaluated together.

values - The values associated with each context.

Returns:

An array of the probabilities for each of the different outcomes, all of which sum to 1.

eval

public double[] eval(String[] context,
 double[] probs)

Evaluates a context.

Parameters:

context - An array of String names of the contextual predicates which are to be evaluated together.

probs - An array which is populated with the probabilities for each of the different outcomes, all of which sum to 1.

Returns:

An array of the probabilities for each of the different outcomes, all of which sum to 1.

eval

public double[] eval(String[] context,
 float[] values,
 double[] outsums)

eval

public static double[] eval(int[] context,
 double[] prior,
 EvalParameters model)

Evaluates a PerceptronModel.

Parameters:

context - The context parameters as int[].

prior - The data prior to the evaluation as double[].

model - The EvalParameters used for evaluation.

Returns:

The resulting evaluation data as double[].

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractModel

equals

public boolean equals(Object obj)

Overrides:

equals in class AbstractModel