burlap.oomdp.core.states

Interface State

All Known Subinterfaces:

BeliefState, ImmutableStateInterface

All Known Implementing Classes:

FixedSizeImmutableState, HashableState, HashableState.CachedHashableState, HashableTabularBeliefStateFactory.HashableTabularBeliefState, ImmutableState, ImmutableStateHashableStateFactory.ImmutableHashableState, MutableState, OOMDPState, SimpleHashableStateFactory.SimpleCachedHashableState, SimpleHashableStateFactory.SimpleHashableState, TabularBeliefState

public interface State

A State instance is used to define the state of an environment or an observation from the environment. This interface provides common methods for working with states that are represented with the the OO-MDP paradigm in which states are a collection of objects (defined with the ObjectInstance interface). Each object has its own value assignment to a set of attributes. OO-MDPs can represent a very large range of different kinds of MDP problems and so you can typically formulate any MDP state as an OO-MDP state. Two standard implementations of State include MutableState and ImmutableState which store state information as explicit collections of MutableObjectInstance and ImmutableObjectInstance objects. However, in special cases and for efficiency reasons, you may want make a custom implementation of State that maintains state information in a different way. For full compatibility with all BURLAP tools, like the Visualizer, and for making using of the existing HashableStateFactory implementations, you should make sure you implement the OO-MDP methods of this interface, even if your State implementation does not explicitly store some collection of ObjectInstance elements. However, if you are willing to write your own implementations of those tools for a custom State implementation that does not implement all the methods, you can do so. For example, If your State implementation does not implement all OO-MDP methods, you can write your own HashableStateFactory to work with it and then use any BURLAP tabular planning or learning algorithm, like AStar, ValueIteration, etc.

Author:

James MacGlashan

Method Summary

Methods

Modifier and Type	Method and Description
State	addAllObjects(java.util.Collection<ObjectInstance> objects) Adds the collection of objects to the state
State	addObject(ObjectInstance o) Adds object instance o to this state.
State	copy() Returns a copy of this state, if mutable the copy should be deep.
java.util.List<ObjectInstance>	getAllObjects() Returns the list of observable and hidden object instances in this state.
java.util.List<java.util.List<ObjectInstance>>	getAllObjectsByClass() Returns a list of list of object instances, grouped by object class
java.util.Map<java.lang.String,java.util.List<java.lang.String>>	getAllUnsetAttributes() Returns a mapping from object instance names to the list of attributes names that have unset values.
java.lang.String	getCompleteStateDescription() Returns a string representation of this state using observable and hidden object instances.
java.lang.String	getCompleteStateDescriptionWithUnsetAttributesAsNull() Returns a string description of the state with unset attribute values listed as null.
ObjectInstance	getFirstObjectOfClass(java.lang.String oclass) Returns the first indexed object of the object class named oclass
ObjectInstance	getObject(java.lang.String oname) Returns the object in this state with the name oname
java.util.Set<java.lang.String>	getObjectClassesPresent() Returns a set of of the object class names for all object classes that have instantiated objects in this state.
java.util.Map<java.lang.String,java.lang.String>	getObjectMatchingTo(State so, boolean enforceStateExactness) This method computes a matching from objects in the receiver to value-identical objects in the parameter state so.
java.util.List<ObjectInstance>	getObjectsOfClass(java.lang.String oclass) Returns all objects that belong to the object class named oclass
java.util.List<java.util.List<java.lang.String>>	getPossibleBindingsGivenParamOrderGroups(java.lang.String[] paramClasses, java.lang.String[] paramOrderGroups) Given an array of parameter object classes and an array of their corresponding parameter order groups, returns all possible object instance bindings to the parameters, excluding bindings that are equivalent due to the parameter order grouping.
int	numTotalObjects() Returns the number of object instances in this state.
State	removeAllObjects(java.util.Collection<ObjectInstance> objects) Removes the collection of objects from the state
State	removeObject(ObjectInstance o) Removes the object instance o from this state.
State	removeObject(java.lang.String oname) Removes the object instance with the name oname from this state.
State	renameObject(ObjectInstance o, java.lang.String newName) Renames the identifier for object instance o in this state to newName.
State	renameObject(java.lang.String originalName, java.lang.String newName) Renames the identifier for the object instance currently named originalName with the name newName.
<T> State	setObjectsValue(java.lang.String objectName, java.lang.String attName, T value)

Method Detail

copy

State copy()

Returns a copy of this state, if mutable the copy should be deep.

Returns:

a copy of this state.

addObject

State addObject(ObjectInstance o)

Adds object instance o to this state.

Parameters:

o - the object instance to be added to this state.

Returns:

the modified state

addAllObjects

State addAllObjects(java.util.Collection<ObjectInstance> objects)

Adds the collection of objects to the state

Parameters:

objects -

Returns:

the modified state

removeObject

State removeObject(java.lang.String oname)

Removes the object instance with the name oname from this state.

Parameters:

oname - the name of the object instance to remove.

Returns:

the modified state

setObjectsValue

<T> State setObjectsValue(java.lang.String objectName,
                        java.lang.String attName,
                        T value)

removeObject

State removeObject(ObjectInstance o)

Removes the object instance o from this state.

Parameters:

o - the object instance to remove from this state.

Returns:

the modified state

removeAllObjects

State removeAllObjects(java.util.Collection<ObjectInstance> objects)

Removes the collection of objects from the state

Parameters:

objects -

Returns:

the modified state

renameObject

State renameObject(java.lang.String originalName,
                 java.lang.String newName)

Renames the identifier for the object instance currently named originalName with the name newName.

Parameters:

originalName - the original name of the object instance to be renamed in this state

newName - the new name of the object instance

Returns:

the modified state

renameObject

State renameObject(ObjectInstance o,
                 java.lang.String newName)

Renames the identifier for object instance o in this state to newName.

Parameters:

o - the object instance to rename in this state

newName - the new name of the object instance

Returns:

the modified state

getObjectMatchingTo

java.util.Map<java.lang.String,java.lang.String> getObjectMatchingTo(State so,
                                                                   boolean enforceStateExactness)

This method computes a matching from objects in the receiver to value-identical objects in the parameter state so. The matching is returned as a map from the object names in the receiving state to the matched objects in state so. If enforceStateExactness is set to true, then the returned matching will be an empty map if the two states are not OO-MDP-wise identical (i.e., if there is a not a bijection between value-identical objects of the two states). If enforceExactness is false and the states are not identical, the the method will return the largest matching between objects that can be made.

Parameters:

so - the state to whose objects the receiving state's objects should be matched

enforceStateExactness - whether to require that states are identical to return a matching

Returns:

a matching from this receiving state's objects to objects in so that have identical values.

numTotalObjects

int numTotalObjects()

Returns the number of object instances in this state.

Returns:

the number of object instances in this state.

getObject

ObjectInstance getObject(java.lang.String oname)

Returns the object in this state with the name oname

Parameters:

oname - the name of the object instance to return

Returns:

the object instance with the name oname or null if there is no object in this state named oname

getAllObjects

java.util.List<ObjectInstance> getAllObjects()

Returns the list of observable and hidden object instances in this state.

Returns:

the list of observable and hidden object instances in this state.

getObjectsOfClass

java.util.List<ObjectInstance> getObjectsOfClass(java.lang.String oclass)

Returns all objects that belong to the object class named oclass

Parameters:

oclass - the name of the object class for which objects should be returned

Returns:

all objects that belong to the object class named oclass

getFirstObjectOfClass

ObjectInstance getFirstObjectOfClass(java.lang.String oclass)

Returns the first indexed object of the object class named oclass

Parameters:

oclass - the name of the object class for which the first indexed object should be returned.

Returns:

the first indexed object of the object class named oclass

getObjectClassesPresent

java.util.Set<java.lang.String> getObjectClassesPresent()

Returns a set of of the object class names for all object classes that have instantiated objects in this state.

Returns:

a set of of the object class names for all object classes that have instantiated objects in this state.

getAllObjectsByClass

java.util.List<java.util.List<ObjectInstance>> getAllObjectsByClass()

Returns a list of list of object instances, grouped by object class

Returns:

a list of list of object instances, grouped by object class

getCompleteStateDescription

java.lang.String getCompleteStateDescription()

Returns a string representation of this state using observable and hidden object instances.

Returns:

a string representation of this state using observable and hidden object instances.

getAllUnsetAttributes

java.util.Map<java.lang.String,java.util.List<java.lang.String>> getAllUnsetAttributes()

Returns a mapping from object instance names to the list of attributes names that have unset values.

Returns:

a mapping from object instance names to the list of attributes names that have unset values.

getCompleteStateDescriptionWithUnsetAttributesAsNull

java.lang.String getCompleteStateDescriptionWithUnsetAttributesAsNull()

Returns a string description of the state with unset attribute values listed as null. This avoids runtime exceptions when attributes are unset and informs you which they are.

Returns:

a string description of the state with unset attribute values listed as null.

getPossibleBindingsGivenParamOrderGroups

java.util.List<java.util.List<java.lang.String>> getPossibleBindingsGivenParamOrderGroups(java.lang.String[] paramClasses,
                                                                                        java.lang.String[] paramOrderGroups)

Given an array of parameter object classes and an array of their corresponding parameter order groups, returns all possible object instance bindings to the parameters, excluding bindings that are equivalent due to the parameter order grouping.

Parameters:

paramClasses - the name of object classes to which the bound object instances must belong

paramOrderGroups - the parameter order group names.

Returns:

A list of all possible object instance bindings for the parameters, were a binding is represented by a list of object instance names