edu.ucla.sspace.index

Class TernaryPermutationFunction

java.lang.Object

edu.ucla.sspace.index.TernaryPermutationFunction

All Implemented Interfaces:

PermutationFunction<TernaryVector>, Serializable

public class TernaryPermutationFunction
extends Object
implements PermutationFunction<TernaryVector>, Serializable

A permutation function that is optimized for TernaryVector instances. This class precomputes the permutations as necessary and only requires O(k) time to compute a single permutation, where k is the number of non-zero elements in the TernaryVector.

Author:

David Jurgens

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TernaryPermutationFunction() Creates an empty DefaultPermutationFunction.

Method Summary

Methods

Modifier and Type	Method and Description
TernaryVector	permute(TernaryVector v, int numPermutations) An optimized instance of permute for TernaryVectors.
String	toString() Returns the name of this class

Methods inherited from class java.lang.Object

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

Constructor Detail

TernaryPermutationFunction

public TernaryPermutationFunction()

Creates an empty DefaultPermutationFunction.

Method Detail

permute

public TernaryVector permute(TernaryVector v,
                    int numPermutations)

An optimized instance of permute for TernaryVectors. In this case, only the positive and negative values are permuted, and a TernaryVector is returned.

Specified by:

permute in interface PermutationFunction<TernaryVector>

Parameters:

v - an index vector to permute

numPermutations - the number of times the permutation function should be applied to the provided index vector.

Returns:

the original index vector permuted the specified number of times

toString

public String toString()

Returns the name of this class

Overrides:

toString in class Object