net.sourceforge.jabm.learning
Class SoftMaxActionSelector

java.lang.Object
  net.sourceforge.jabm.learning.SoftMaxActionSelector

All Implemented Interfaces:

ActionSelector

public class SoftMaxActionSelector
extends java.lang.Object
implements ActionSelector

An implementation of the softmax action selection policy.

See:
Sutton, R. S., Barto, A. G., 1998. Reinforcement Learning: An Introduction. MIT Press.

Field Summary

protected cern.jet.random.engine.RandomEngine	prng
protected double	tau The "temperature" used to modulate the propensity distribution.

Constructor Summary

SoftMaxActionSelector()

SoftMaxActionSelector(cern.jet.random.engine.RandomEngine prng, double tau)

Method Summary

int	act(int state, MDPLearner learner) Choose an action according to the current state and the current value estimates for each action.
cern.jet.random.engine.RandomEngine	getPrng()
double	getTau()
void	setPrng(cern.jet.random.engine.RandomEngine prng)
void	setTau(double tau)

Methods inherited from class java.lang.Object

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

Field Detail

prng

protected cern.jet.random.engine.RandomEngine prng

tau

protected double tau

The "temperature" used to modulate the propensity distribution.

Constructor Detail

SoftMaxActionSelector

public SoftMaxActionSelector()

SoftMaxActionSelector

public SoftMaxActionSelector(cern.jet.random.engine.RandomEngine prng,
                             double tau)

Method Detail

act

public int act(int state,
               MDPLearner learner)

Description copied from interface: ActionSelector

Choose an action according to the current state and the current value estimates for each action.

Specified by:

act in interface ActionSelector

Parameters:

state - The current state of the MDP.

learner - The algorithm used to update the value estimates.

Returns:

An integer representing the action chosen (indexed from 0).

getPrng

public cern.jet.random.engine.RandomEngine getPrng()

setPrng

public void setPrng(cern.jet.random.engine.RandomEngine prng)

getTau

public double getTau()

setTau

public void setTau(double tau)

Parameters:

tau - The "temperature" used to modulate the propensities.