burlap.behavior.functionapproximation

Interface FunctionGradient

All Known Implementing Classes:

FunctionGradient.SparseGradient

public interface FunctionGradient

An interface for defining and querying the gradient of a function.

Author:

James MacGlashan

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	FunctionGradient.PartialDerivative A class for storing a partial derivative.
static class	FunctionGradient.SparseGradient A sparse FunctionGradient that only explicitly stores the partial derivative for parameters with non-zero partial derivatives.

Method Summary

Modifier and Type	Method and Description
java.util.Set<FunctionGradient.PartialDerivative>	getNonZeroPartialDerivatives() Returns all non-zero partial derivatives.
double	getPartialDerivative(int parameterId) Returns the partial derivative for the given weight
int	numNonZeroPDs() Returns the number of non-zero partial derivatives
void	put(int parameterId, double partialDerivative) Adds the partial derivative for a given weight

Method Detail

put

void put(int parameterId,
         double partialDerivative)

Adds the partial derivative for a given weight

Parameters:

parameterId - the parameter identifier for which the partial derivative is to be stored.

partialDerivative - the partial derivative value for the parameter

getPartialDerivative

double getPartialDerivative(int parameterId)

Returns the partial derivative for the given weight

Parameters:

parameterId - the parameter for which the partial derivative will be returned

Returns:

the partial derivative for the given weight; 0 if it is not stored.

getNonZeroPartialDerivatives

java.util.Set<FunctionGradient.PartialDerivative> getNonZeroPartialDerivatives()

Returns all non-zero partial derivatives. Result is stored in a Map.Entry where the key is an Integer of the parameter identifier and the value is a double specifying its partial derivative.

Returns:

all non-zero partial derivatives.

numNonZeroPDs

int numNonZeroPDs()

Returns the number of non-zero partial derivatives

Returns:

the number of non-zero partial derivatives