edu.stanford.nlp.classify

Class LogisticObjectiveFunction

java.lang.Object

edu.stanford.nlp.optimization.AbstractCachingDiffFunction

edu.stanford.nlp.classify.LogisticObjectiveFunction

All Implemented Interfaces:

DiffFunction, Function, HasInitial

public class LogisticObjectiveFunction
extends AbstractCachingDiffFunction

Maximizes the conditional likelihood with a given prior. Because the problem is binary, optimizations are possible that cannot be done in LogConditionalObjectiveFunction.

Author:

Galen Andrew

Field Summary

Fields

Modifier and Type	Field and Description
protected float[]	dataweights

Fields inherited from class edu.stanford.nlp.optimization.AbstractCachingDiffFunction

derivative, generator, value

Constructor Summary

Constructors

Constructor and Description
LogisticObjectiveFunction(int numFeatures, int[][] data, double[][] values, int[] labels)
LogisticObjectiveFunction(int numFeatures, int[][] data, double[][] values, int[] labels, float[] dataweights)
LogisticObjectiveFunction(int numFeatures, int[][] data, double[][] values, int[] labels, LogPrior prior)
LogisticObjectiveFunction(int numFeatures, int[][] data, double[][] values, int[] labels, LogPrior prior, float[] dataweights)
LogisticObjectiveFunction(int numFeatures, int[][] data, int[] labels)
LogisticObjectiveFunction(int numFeatures, int[][] data, int[] labels, float[] dataweights)
LogisticObjectiveFunction(int numFeatures, int[][] data, int[] labels, LogPrior prior)
LogisticObjectiveFunction(int numFeatures, int[][] data, int[] labels, LogPrior prior, float[] dataweights)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	calculate(double[] x) Calculate the value at x and the derivative and save them in the respective fields.
protected void	calculateRVF(double[] x)
int	domainDimension() Returns the number of dimensions in the function's domain

Methods inherited from class edu.stanford.nlp.optimization.AbstractCachingDiffFunction

clearCache, copy, derivativeAt, ensure, getDerivative, gradientCheck, gradientCheck, initial, lastValue, randomInitial, valueAt

Methods inherited from class java.lang.Object

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

Field Detail

dataweights

protected float[] dataweights

Constructor Detail

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         int[] labels)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         int[] labels,
                         LogPrior prior)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         int[] labels,
                         float[] dataweights)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         int[] labels,
                         LogPrior prior,
                         float[] dataweights)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         double[][] values,
                         int[] labels)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         double[][] values,
                         int[] labels,
                         LogPrior prior)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         double[][] values,
                         int[] labels,
                         float[] dataweights)

LogisticObjectiveFunction

public LogisticObjectiveFunction(int numFeatures,
                         int[][] data,
                         double[][] values,
                         int[] labels,
                         LogPrior prior,
                         float[] dataweights)

Method Detail

domainDimension

public int domainDimension()

Description copied from interface: Function

Returns the number of dimensions in the function's domain

Returns:

the number of domain dimensions

calculate

protected void calculate(double[] x)

Description copied from class: AbstractCachingDiffFunction

Calculate the value at x and the derivative and save them in the respective fields.

Specified by:

calculate in class AbstractCachingDiffFunction

Parameters:

x - The point at which to calculate the function

calculateRVF

protected void calculateRVF(double[] x)