burlap.behavior.stochasticgames.madynamicprogramming

Class QSourceForSingleAgent.HashBackedQSource

java.lang.Object

burlap.behavior.stochasticgames.madynamicprogramming.QSourceForSingleAgent.HashBackedQSource

All Implemented Interfaces:

QSourceForSingleAgent

Enclosing interface:

QSourceForSingleAgent

public static class QSourceForSingleAgent.HashBackedQSource
extends java.lang.Object
implements QSourceForSingleAgent

An implementation of the QSourceForSingleAgent interface that has Q-values backed by hashmaps. Specifically, a map from hashed stats to a map from joint actions to stored JAQValue objects. This object also takes as QFunction object so that Q-values for state-joint-action pairs not previously stored can be initialized.

Author:

James MacGlashan

Nested Class Summary

Nested classes/interfaces inherited from interface burlap.behavior.stochasticgames.madynamicprogramming.QSourceForSingleAgent

QSourceForSingleAgent.HashBackedQSource

Field Summary

Fields

Modifier and Type	Field and Description
protected HashableStateFactory	hashingFactory
protected QFunction	qInit
protected java.util.HashMap<HashableState,java.util.Map<JointAction,JAQValue>>	qValues

Constructor Summary

Constructors

Constructor and Description
HashBackedQSource(HashableStateFactory hashingFactory, QFunction qInit) Initializes with a given state hashing factory and value funciton initialization for Q-values.

Method Summary

Modifier and Type	Method and Description
protected java.util.Map<JointAction,JAQValue>	getJAMap(State s) Returns the Map from joint actions to q-values for a given state.
JAQValue	getQValueFor(State s, JointAction ja) Returns a Q-value (represented with a JAQValue object) stored for the given state and joint action.

Methods inherited from class java.lang.Object

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

Field Detail

qValues

protected java.util.HashMap<HashableState,java.util.Map<JointAction,JAQValue>> qValues

hashingFactory

protected HashableStateFactory hashingFactory

qInit

protected QFunction qInit

Constructor Detail

HashBackedQSource

public HashBackedQSource(HashableStateFactory hashingFactory,
                         QFunction qInit)

Initializes with a given state hashing factory and value funciton initialization for Q-values.

Parameters:

hashingFactory - the state hashing factory used to index states

qInit - the value function intitliazaiton to use for previously unqueried states

Method Detail

getQValueFor

public JAQValue getQValueFor(State s,
                             JointAction ja)

Description copied from interface: QSourceForSingleAgent

Returns a Q-value (represented with a JAQValue object) stored for the given state and joint action. Modification to the returned object will directly modify the stored value that will be returned in subsequent calls to this method.

Specified by:

getQValueFor in interface QSourceForSingleAgent

Parameters:

s - the Q-value's associated state

ja - the Q-value's associated joint aciton

Returns:

a JAQValue for the given state and joint action.

getJAMap

protected java.util.Map<JointAction,JAQValue> getJAMap(State s)

Returns the Map from joint actions to q-values for a given state. If the map does not already exist, then it is created and indexed.

Parameters:

s - the state for which the map is returned.

Returns:

the Map from joint actions to q-values for a given state