burlap.behavior.functionapproximation.dense.rbf

Class RBFFeatures

java.lang.Object

burlap.behavior.functionapproximation.dense.rbf.RBFFeatures

All Implemented Interfaces:

DenseStateFeatures

public class RBFFeatures
extends java.lang.Object
implements DenseStateFeatures

A feature database of RBF units that can be used for linear value function approximation. This class takes as input a DenseStateFeatures object so that states are first converted to a double array and then provided to RBF objects that operate directly on the feature vector of the state.

Author:

James MacGlashan.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Map<Action,java.lang.Integer>	actionFeatureMultiplier A map for returning a multiplier to the number of RBF state features for each action.
protected boolean	hasOffset Specifies whether an offset RBF unit with a constant response value is included in the feature set.
protected DenseStateFeatures	inputFeatures The input features over which RBFs will be generated
protected int	nextActionMultiplier The next action RBF size multiplier to use for the next newly seen action.
protected int	nRbfs The number of RBF units, not including an offset unit.
protected java.util.List<RBF>	rbfs The list of RBF units in this database

Constructor Summary

Constructors

Constructor and Description
RBFFeatures(DenseStateFeatures inputFeatures, boolean hasOffset) Initializes with an empty list of RBF units.

Method Summary

Modifier and Type	Method and Description
void	addRBF(RBF rbf) Adds the specified RBF unit to the list of RBF units.
void	addRBFs(java.util.List<RBF> rbfs) Adds all of the specified RBF units to this object's list of RBF units.
RBFFeatures	copy() Returns a copy of this DenseStateFeatures
double[]	features(State s) Returns a feature vector represented as a double array for a given input state.
DenseLinearVFA	generateVFA(double defaultWeightValue) Creates and returns a linear VFA object over this RBF feature database.

Methods inherited from class java.lang.Object

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

Field Detail

inputFeatures

protected DenseStateFeatures inputFeatures

The input features over which RBFs will be generated

rbfs

protected java.util.List<RBF> rbfs

The list of RBF units in this database

nRbfs

protected int nRbfs

The number of RBF units, not including an offset unit.

hasOffset

protected boolean hasOffset

Specifies whether an offset RBF unit with a constant response value is included in the feature set.

actionFeatureMultiplier

protected java.util.Map<Action,java.lang.Integer> actionFeatureMultiplier

A map for returning a multiplier to the number of RBF state features for each action. Effectively this ensures a unique feature ID for each RBF for each action.

nextActionMultiplier

protected int nextActionMultiplier

The next action RBF size multiplier to use for the next newly seen action.

Constructor Detail

RBFFeatures

public RBFFeatures(DenseStateFeatures inputFeatures,
                   boolean hasOffset)

Initializes with an empty list of RBF units.

Parameters:

inputFeatures - the input features over which RBFs will be generated

hasOffset - if true, an offset RBF unit with a constant response value is included in the feature set.

Method Detail

addRBF

public void addRBF(RBF rbf)

Adds the specified RBF unit to the list of RBF units.

Parameters:

rbf - the RBF unit to add.

addRBFs

public void addRBFs(java.util.List<RBF> rbfs)

Adds all of the specified RBF units to this object's list of RBF units.

Parameters:

rbfs - the RBF units to add.

features

public double[] features(State s)

Description copied from interface: DenseStateFeatures

Returns a feature vector represented as a double array for a given input state.

Specified by:

features in interface DenseStateFeatures

Parameters:

s - the input state to turn into a feature vector.

Returns:

the feature vector represented as a double array.

generateVFA

public DenseLinearVFA generateVFA(double defaultWeightValue)

Creates and returns a linear VFA object over this RBF feature database.

Parameters:

defaultWeightValue - the default feature weight value to use for all features

Returns:

a linear VFA object over this RBF feature database.

copy

public RBFFeatures copy()

Description copied from interface: DenseStateFeatures

Returns a copy of this DenseStateFeatures

Specified by:

copy in interface DenseStateFeatures

Returns:

a copy of this DenseStateFeatures