edu.memphis.ccrg.lida.episodicmemory.sdm
Class BitVectorUtils

java.lang.Object
  edu.memphis.ccrg.lida.episodicmemory.sdm.BitVectorUtils

public class BitVectorUtils
extends java.lang.Object

Utilities for BitVector

Author:

Javier Snaider

Constructor Summary

BitVectorUtils()

Method Summary

static cern.colt.bitvector.BitVector	getComplement(cern.colt.bitvector.BitVector a) Gets the complement of a bit vector.
static cern.colt.bitvector.BitVector	getNoisyVector(cern.colt.bitvector.BitVector original, int noise) Returns a noisy BitVector
static cern.colt.bitvector.BitVector	getNormalizedVector(int[] buff) Gets a normalized vector.
static cern.colt.bitvector.BitVector	getRandomVector(int s) Returns a random BitVector of specified size
static int[]	getVectorSum(int[] accum, cern.colt.bitvector.BitVector v) Adds a BitVector to an accumulation array.
static int[]	getVectorSum(int[] accum, int[] vector) Sums specified vectors.
static int	hamming(cern.colt.bitvector.BitVector vector1, cern.colt.bitvector.BitVector vector2) Calculates the Hamming distances between two BitVector addresses.
static cern.colt.bitvector.BitVector	multiplyVectors(cern.colt.bitvector.BitVector a, cern.colt.bitvector.BitVector b) Multiply vectors.
static int[]	vectorToBipolar(cern.colt.bitvector.BitVector v) Vector to bipolar.
static int[]	vectorToBipolar(int[] accum, cern.colt.bitvector.BitVector v) Vector to bipolar.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitVectorUtils

public BitVectorUtils()

Method Detail

getRandomVector

public static cern.colt.bitvector.BitVector getRandomVector(int s)

Returns a random BitVector of specified size

Parameters:

s - the size of the new vector

Returns:

a new random vector of size s.

hamming

public static int hamming(cern.colt.bitvector.BitVector vector1,
                          cern.colt.bitvector.BitVector vector2)

Calculates the Hamming distances between two BitVector addresses.

Parameters:

vector1 - the first BitVector

vector2 - the second BitVector

Returns:

the Hamming distances

getNoisyVector

public static cern.colt.bitvector.BitVector getNoisyVector(cern.colt.bitvector.BitVector original,
                                                           int noise)

Returns a noisy BitVector

Parameters:

original - original BitVector

noise - number of noisy bits to introduce

Returns:

a new vector which differs from the original by at most 'noise' bits

getVectorSum

public static int[] getVectorSum(int[] accum,
                                 cern.colt.bitvector.BitVector v)

Adds a BitVector to an accumulation array. The bits of the BitVector are first converted to either 0 to -1. The BitVector is not modified.

Parameters:

accum - the accumulation array.

v - the vector to be added

Returns:

the new accumulation array

getVectorSum

public static int[] getVectorSum(int[] accum,
                                 int[] vector)

Sums specified vectors.

Parameters:

accum - the accum

vector - the vector

Returns:

the int[]

vectorToBipolar

public static int[] vectorToBipolar(int[] accum,
                                    cern.colt.bitvector.BitVector v)

Vector to bipolar.

Parameters:

accum - the accum

v - the v

Returns:

the int[]

vectorToBipolar

public static int[] vectorToBipolar(cern.colt.bitvector.BitVector v)

Vector to bipolar.

Parameters:

v - the v

Returns:

the int[]

getNormalizedVector

public static cern.colt.bitvector.BitVector getNormalizedVector(int[] buff)

Gets a normalized vector.

Parameters:

buff - a int[] vector

Returns:

new normalized BitVector

multiplyVectors

public static cern.colt.bitvector.BitVector multiplyVectors(cern.colt.bitvector.BitVector a,
                                                            cern.colt.bitvector.BitVector b)

Multiply vectors.

Parameters:

a - the a

b - the b

Returns:

the bit vector

getComplement

public static cern.colt.bitvector.BitVector getComplement(cern.colt.bitvector.BitVector a)

Gets the complement of a bit vector.

Parameters:

a - the input bit vector

Returns:

the complement of the input bit vector