ptolemy.data.ontologies.lattice

Class ProductLatticeCPO

java.lang.Object

ptolemy.data.ontologies.ConceptGraph

ptolemy.data.ontologies.lattice.ProductLatticeCPO

All Implemented Interfaces:

CPO<Concept>

public class ProductLatticeCPO
extends ConceptGraph

A complete partial order for product lattice-based ontologies. Given a product lattice defined by a list of ProductLatticeConcepts, this class provides the implementation for all complete partial order operations on the product lattice. Note that this complete partial order implementation is not derived from a graph of the concepts, but rather by doing comparison operations that depend on the structure of the individual lattices that comprise the product lattice. For example, take a product lattice P that is composed of two lattices L1 and L2. Each lattice element concept in P is a tuple of the form <C(L1), C(L2)>. To decide the relationship between two concepts in p1 and p2 in P, it is determined by the relationships of the individual concepts in their tuples. So: p1 ≥ p2 iff C1(L1) ≥ C2(L1) and C1(L2) ≥ C2(L2)

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Charles Shelton

Pt.AcceptedRating:

Red (cshelton)

Pt.ProposedRating:

Red (cshelton)

Nested Class Summary

Nested classes/interfaces inherited from interface ptolemy.graph.CPO

CPO.BoundType

Field Summary

Fields inherited from interface ptolemy.graph.CPO

HIGHER, INCOMPARABLE, LOWER, SAME

Constructor Summary

Constructors

Constructor and Description
ProductLatticeCPO(ProductLatticeOntology productOntology) Create a new ProductLatticeCPO from the given list of ProductLatticeConcepts.

Method Summary

Modifier and Type	Method and Description
Concept	bottom() Return the bottom element of this CPO.
int	compare(java.lang.Object e1, java.lang.Object e2) Compare two concepts in the product lattice ontology.
ProductLatticeConcept[]	downSet(java.lang.Object e) Compute the down-set of an element in this concept graph.
Concept	greatestLowerBound(java.lang.Object e1, java.lang.Object e2) Compute the greatest lower bound (GLB) of two elements.
Concept	leastUpperBound(java.lang.Object e1, java.lang.Object e2) Compute the least upper bound (LUB) of two elements.
NonProductLatticeCounterExample	nonLatticeReason() Return the reason why this CPO is not a lattice, or null if it is.
Concept	top() Return the top element of this CPO.

Methods inherited from class ptolemy.data.ontologies.ConceptGraph

greatestElement, greatestLowerBound, isLattice, leastElement, leastUpperBound, upSet

Methods inherited from class java.lang.Object

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

Constructor Detail

ProductLatticeCPO

public ProductLatticeCPO(ProductLatticeOntology productOntology)

Create a new ProductLatticeCPO from the given list of ProductLatticeConcepts.

Parameters:

productOntology - The product lattice ontology for which this CPO is a complete partial order.

Method Detail

bottom

public Concept bottom()

Return the bottom element of this CPO. The bottom element is the element in the CPO that is lower than all the other elements.

Specified by:

bottom in interface CPO<Concept>

Specified by:

bottom in class ConceptGraph

Returns:

An Object representing the bottom element, or null if the bottom does not exist.

compare

public int compare(java.lang.Object e1,
                   java.lang.Object e2)

Compare two concepts in the product lattice ontology. The arguments must be instances of ProductLatticeConcept, otherwise an exception will be thrown. This method returns one of ptolemy.graph.CPO.LOWER, ptolemy.graph.CPO.SAME, ptolemy.graph.CPO.HIGHER, ptolemy.graph.CPO.INCOMPARABLE, indicating the first argument is lower than, equal to, higher than, or incomparable with the second argument in the product lattice hierarchy, respectively.

Specified by:

compare in interface CPO<Concept>

Specified by:

compare in class ConceptGraph

Parameters:

e1 - An instance of ProductLatticeConcept.

e2 - An instance of ProductLatticeConcept.

Returns:

One of CPO.LOWER, CPO.SAME, CPO.HIGHER, CPO.INCOMPARABLE.

Throws:

java.lang.IllegalArgumentException - If one or both arguments are not instances of ProductLatticeConcept, the arguments are not from the same ontology, or either argument has an empty or null concept tuple list.

downSet

public ProductLatticeConcept[] downSet(java.lang.Object e)

Compute the down-set of an element in this concept graph. This is implemented by deferring to the downSet functions of the component graphs and then enumerating all the product results.

Specified by:

downSet in interface CPO<Concept>

Overrides:

downSet in class ConceptGraph

Parameters:

e - An Object representing a ProductLatticeConcept in this concept graph.

Returns:

An array of ProductLatticeConcepts of the down-set of the given argument concept.

Throws:

java.lang.IllegalArgumentException - If the passed object is not a ProductLatticeConcept or does not belong to this CPO.

greatestLowerBound

public Concept greatestLowerBound(java.lang.Object e1,
                                  java.lang.Object e2)

Compute the greatest lower bound (GLB) of two elements. The GLB of two elements is the greatest element in the CPO that is lower than or the same as both of the two elements.

Specified by:

greatestLowerBound in interface CPO<Concept>

Overrides:

greatestLowerBound in class ConceptGraph

Parameters:

e1 - An Object representing an element in this CPO.

e2 - An Object representing an element in this CPO.

Returns:

An Object representing the GLB of the two specified elements, or null if the GLB does not exist.

Throws:

java.lang.IllegalArgumentException - Thrown if the product lattice concept greatest lower bound cannot be created from the component greatest lower bound concepts.

nonLatticeReason

public NonProductLatticeCounterExample nonLatticeReason()

Return the reason why this CPO is not a lattice, or null if it is. A Product Lattice CPO is a lattice if all of its component ontologies are lattices.

Specified by:

nonLatticeReason in class ConceptGraph

Returns:

A string representing which subontology is responsible for this not being a lattice; null otherwise.

leastUpperBound

public Concept leastUpperBound(java.lang.Object e1,
                               java.lang.Object e2)

Compute the least upper bound (LUB) of two elements. The LUB of two elements is the least element in the CPO that is greater than or the same as both of the two elements.

Specified by:

leastUpperBound in interface CPO<Concept>

Specified by:

leastUpperBound in class ConceptGraph

Parameters:

e1 - An Object representing an element in this CPO.

e2 - An Object representing an element in this CPO.

Returns:

Nothing.

Throws:

java.lang.IllegalArgumentException - Thrown if the product lattice concept least upper bound cannot be created from the component least upper bound concepts.

top

public Concept top()

Return the top element of this CPO. The top element is the element in the CPO that is higher than all the other elements.

Specified by:

top in interface CPO<Concept>

Specified by:

top in class ConceptGraph

Returns:

An Object representing the top element, or null if the top does not exist.