burlap.behavior.singleagent.vfa.rbf.functions

Class GaussianRBF

java.lang.Object

burlap.behavior.singleagent.vfa.rbf.RBF

burlap.behavior.singleagent.vfa.rbf.functions.GaussianRBF

public class GaussianRBF
extends RBF

An RBF whose response is dictated by a Gaussian kernel. More specifically, this RBF returns e^(-1 * d(x, c)^2 / e^2), where d(x, c) is the distance from a query state s to a defined "center," c, of this RBF and e is a bandwidth parameter on (0, +infinity) that affects the range of influence of this RBF. The larger the bandwidth value, the more uniform the response it gives to any arbitrary input state. The distance between the query state and the center state is determined by a provided distance function.

Author:

Anubhav Malhotra and Daniel Fernandez and Spandan Dutta

Field Summary

Fields

Modifier and Type	Field and Description
protected double	epsilon The bandwidth parameter.

Fields inherited from class burlap.behavior.singleagent.vfa.rbf.RBF

centeredState, metric

Constructor Summary

Constructors

Constructor and Description
GaussianRBF(State centerdState, DistanceMetric metric, double epsilon) Initializes with a center state, a distance metric and a bandwidth parameter.

Method Summary

Methods

Modifier and Type	Method and Description
static java.util.List<RBF>	generateGaussianRBFsForStates(java.util.List<State> states, DistanceMetric metric, double epsilon) Creates a List of GaussianRBF units for each State provided using the given metric and epsilon value.
double	responseFor(State input) Returns a response value to an input state that is a function of the distance between the input and this unit's center state.

Methods inherited from class java.lang.Object

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

Field Detail

epsilon

protected double epsilon

The bandwidth parameter. The larger the bandwidth value, the more uniform the response it gives to any arbitrary input state.

Constructor Detail

GaussianRBF

public GaussianRBF(State centerdState,
           DistanceMetric metric,
           double epsilon)

Initializes with a center state, a distance metric and a bandwidth parameter.

Parameters:

centerdState - the center state of this RBF unit.

metric - the distance metric to use.

epsilon - the bandwidth parameter.

Method Detail

responseFor

public double responseFor(State input)

Description copied from class: RBF

Returns a response value to an input state that is a function of the distance between the input and this unit's center state. The less distant a query state is from this unit's center state, the greater the resposne value.

Specified by:

responseFor in class RBF

Parameters:

input - the input state for which a response value is returned.

Returns:

a response value to the given input state

generateGaussianRBFsForStates

public static java.util.List<RBF> generateGaussianRBFsForStates(java.util.List<State> states,
                                                DistanceMetric metric,
                                                double epsilon)

Creates a List of GaussianRBF units for each State provided using the given metric and epsilon value.

Parameters:

states - the State objects around which a GaussianRBF will be created

metric - the DistanceMetric to use

epsilon - the bandwidth parameter.

Returns:

a List of GaussianRBF units.