edu.ucla.sspace.index

Class WindowedPermutationFunction

java.lang.Object

edu.ucla.sspace.index.WindowedPermutationFunction

All Implemented Interfaces:

PermutationFunction<Vector>

public class WindowedPermutationFunction
extends Object
implements PermutationFunction<Vector>

A permutation function that provides windows of positions which are permuted using the same function. For instance, with a window size of 2, words 1 and 2 positions away will be permuted once, words 3 and 4 positions away will be permuted twice, etc. This class supports the following properties:

Property:
Default: "1"

This variable sets the size of a permutation window.

Author:

Keith Stevens

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_WINDOW_LIMIT The default window limit to place on permutations.
static String	PROPERTY_PREFIX The prefix for naming public properties.
static String	WINDOW_LIMIT_PROPERTY The property to set the window size.

Constructor Summary

Constructors

Constructor and Description
WindowedPermutationFunction() Creates a WindowedPermutationFunction using the default system Properties.
WindowedPermutationFunction(Properties props) Creates a WindowedPermutationFunction using a passed in Properties.

Method Summary

Methods

Modifier and Type	Method and Description
Vector	permute(Vector v, int numPermutations) Permutes the provided TernaryVector the specified number of times.

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_PREFIX

public static final String PROPERTY_PREFIX

The prefix for naming public properties.

See Also:

Constant Field Values

WINDOW_LIMIT_PROPERTY

public static final String WINDOW_LIMIT_PROPERTY

The property to set the window size.

See Also:

Constant Field Values

DEFAULT_WINDOW_LIMIT

public static final String DEFAULT_WINDOW_LIMIT

The default window limit to place on permutations.

See Also:

Constant Field Values

Constructor Detail

WindowedPermutationFunction

public WindowedPermutationFunction()

Creates a WindowedPermutationFunction using the default system Properties.

WindowedPermutationFunction

public WindowedPermutationFunction(Properties props)

Creates a WindowedPermutationFunction using a passed in Properties.

Method Detail

permute

public Vector permute(Vector v,
             int numPermutations)

Permutes the provided TernaryVector the specified number of times.

Specified by:

permute in interface PermutationFunction<Vector>

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