edu.ksu.cis.projects.bogor.util
Class Relation

java.lang.Object
  edu.ksu.cis.projects.bogor.util.Relation

public class Relation
extends Object

This class provides methods for working with relation/function.

Version:

CVS $Revision: 1.2 $ $Date: 2004/12/18 22:36:34 $

Author:

Robby

Constructor Summary

Relation()

Method Summary

static <K> Map<K,Set<K>>	functionClosure(Map<K,K> fr, boolean sortedDomain, boolean sortedCoDomain) Builds a transitive closure of a function.
static <K> Map<K,Set<K>>	functionInverse(Map<K,K> fr, boolean sortedDomain, boolean sortedCoDomain) Builds an inverse function or relation of a function.
static <K> Map<K,Set<K>>	relationClosure(Map<K,Set<K>> fr, boolean sortedDomain, boolean sortedCoDomain) Builds a transitive closure of a relation.
static <K> Map<K,Set<K>>	relationInverse(Map<K,Set<K>> fr, boolean sortedDomain, boolean sortedCoDomain) Builds an inverse function or relation of a relation.

Methods inherited from class java.lang.Object

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

Constructor Detail

Relation

public Relation()

Method Detail

relationClosure

public static <K> Map<K,Set<K>> relationClosure(Map<K,Set<K>> fr,
                                                boolean sortedDomain,
                                                boolean sortedCoDomain)

Builds a transitive closure of a relation.

Parameters:

fr - The relation. Must be non-null. Each key and value must be non-null.

sortedDomain - Indicates that the resulting domain should be sorted. If true, then fr's domain is Comparable.

sortedCoDomain - Indicates that the resulting co-domain should be a sorted set. If true, then fr's co-domain is Set<Comparable>.

Returns:

The transitive closure of the relation. Non-null.

• If sortedDomain and sortedCoDomain then TreeMap<Comparable, OrderedSet<Comparable>.
• If sortedDomain then TreeMap<Comparable, Set<Object>.
• If sortedCoDomain then Hashtable<Object, OrderedSet<Object>.
• Else, Hashtable<Object, Set<Object>.

functionClosure

public static <K> Map<K,Set<K>> functionClosure(Map<K,K> fr,
                                                boolean sortedDomain,
                                                boolean sortedCoDomain)

Builds a transitive closure of a function.

Parameters:

fr - The function. Must be non-null. Each key and value must be non-null.

sortedDomain - Indicates that the resulting domain should be sorted. If true, then fr's domain is Comparable.

sortedCoDomain - Indicates that the resulting co-domain should be a sorted set. If true, then fr's co-domain is Comparable.

Returns:

The transitive closure of the function. Non-null.

• If sortedDomain and sortedCoDomain then TreeMap<Comparable, OrderedSet<Comparable>.
• If sortedDomain then TreeMap<Comparable, Set<Object>.
• If sortedCoDomain then Hashtable<Object, OrderedSet<Object>.
• Else, Hashtable<Object, Set<Object>.

functionInverse

public static <K> Map<K,Set<K>> functionInverse(Map<K,K> fr,
                                                boolean sortedDomain,
                                                boolean sortedCoDomain)

Builds an inverse function or relation of a function.

Parameters:

fr - The function. Must be non-null. Each key and value must be non-null.

sortedDomain - Indicates that the resulting domain should be sorted. If true, then fr's domain is Comparable.

sortedCoDomain - Indicates that the resulting co-domain should be a sorted set. If true, then fr's co-domain is Comparable.

Returns:

The inverse function or relation of the function. Non-null.

• If sortedDomain and sortedCoDomain then TreeMap<Comparable, OrderedSet<Comparable>.
• Else if sortedDomain then TreeMap<Comparable, Set<Object>.
• Else if sortedCoDomain then Hashtable<Object, OrderedSet<Object>.
• Else, Hashtable<Object, Set<Object>.

relationInverse

public static <K> Map<K,Set<K>> relationInverse(Map<K,Set<K>> fr,
                                                boolean sortedDomain,
                                                boolean sortedCoDomain)

Builds an inverse function or relation of a relation.

Parameters:

fr - The relation. Must be non-null. Each key and value must be non-null.

sortedDomain - Indicates that the resulting domain should be sorted. If true, then fr's domain is Comparable.

sortedCoDomain - Indicates that the resulting co-domain should be a sorted set. If true, then fr's co-domain is Set<Comparable>.

Returns:

The inverse function or relation of the relation. Non-null.

• If sortedDomain and sortedCoDomain then TreeMap<Comparable, OrderedSet<Comparable>.
• Else if sortedDomain then TreeMap<Comparable, Set<Object>.
• Else if sortedCoDomain then Hashtable<Object, OrderedSet<Object>.
• Else, Hashtable<Object, Set<Object>.