edu.stanford.nlp.optimization
Class AbstractCachingDiffFloatFunction

java.lang.Object
  edu.stanford.nlp.optimization.AbstractCachingDiffFloatFunction

All Implemented Interfaces:

DiffFloatFunction, FloatFunction, HasFloatInitial

Direct Known Subclasses:

CRFLogConditionalObjectiveFloatFunction

public abstract class AbstractCachingDiffFloatFunction
extends java.lang.Object
implements DiffFloatFunction, HasFloatInitial

Author:

Dan Klein

Field Summary

protected float[]	derivative
protected float	value

Constructor Summary

AbstractCachingDiffFloatFunction()

Method Summary

protected abstract void	calculate(float[] x) Calculate the value at x and the derivative and save them in the respective fields
protected void	copy(float[] y, float[] x)
float[]	derivativeAt(float[] x) Returns the first-derivative vector at the input location.
abstract int	domainDimension() Returns the number of dimensions in the function's domain
float[]	initial() Returns the intitial point in the domain (but not necessarily a feasible one).
float	valueAt(float[] x) Returns the value of the function at a single point.

Methods inherited from class java.lang.Object

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

Field Detail

derivative

protected float[] derivative

value

protected float value

Constructor Detail

AbstractCachingDiffFloatFunction

public AbstractCachingDiffFloatFunction()

Method Detail

domainDimension

public abstract int domainDimension()

Description copied from interface: FloatFunction

Returns the number of dimensions in the function's domain

Specified by:

domainDimension in interface FloatFunction

Returns:

the number of domain dimensions

calculate

protected abstract void calculate(float[] x)

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

initial

public float[] initial()

Description copied from interface: HasFloatInitial

Returns the intitial point in the domain (but not necessarily a feasible one).

Specified by:

initial in interface HasFloatInitial

Returns:

a domain point

copy

protected void copy(float[] y,
                    float[] x)

valueAt

public float valueAt(float[] x)

Description copied from interface: FloatFunction

Returns the value of the function at a single point.

Specified by:

valueAt in interface FloatFunction

Parameters:

x - a double[] input

Returns:

the function value at the input

derivativeAt

public float[] derivativeAt(float[] x)

Description copied from interface: DiffFloatFunction

Returns the first-derivative vector at the input location.

Specified by:

derivativeAt in interface DiffFloatFunction

Parameters:

x - a double[] input vector

Returns:

the vector of first partial derivatives.