org.openimaj.lsh.functions

Class ShortHammingFactory

java.lang.Object

org.openimaj.lsh.functions.RandomisedHashFunctionFactory<short[]>

org.openimaj.lsh.functions.ShortHashFunctionFactory

org.openimaj.lsh.functions.ShortHammingFactory

All Implemented Interfaces:

HashFunctionFactory<short[]>

@Reference(type=Inproceedings,
           author={"Indyk, Piotr","Motwani, Rajeev"},
           title="Approximate nearest neighbors: towards removing the curse of dimensionality",
           year="1998",
           booktitle="Proceedings of the thirtieth annual ACM symposium on Theory of computing",
           pages={"604","","613"},
           url="http://doi.acm.org/10.1145/276698.276876",
           publisher="ACM",
           series="STOC \'98")
public class ShortHammingFactory
extends ShortHashFunctionFactory

A hash function factory for producing hash functions that approximate the Hamming distance.

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Field Summary

Fields inherited from class org.openimaj.lsh.functions.RandomisedHashFunctionFactory

ndims, rng

Constructor Summary

Constructors

Constructor and Description
ShortHammingFactory(int ndims, cern.jet.random.engine.MersenneTwister rng, int bitsPerDim) Construct a new factory using the given parameters.

Method Summary

Modifier and Type	Method and Description
org.openimaj.lsh.functions.ShortHammingFactory.Function	create() Construct a new HashFunction.
ShortFVComparison	fvDistanceFunction()

Methods inherited from class org.openimaj.lsh.functions.ShortHashFunctionFactory

distanceFunction

Methods inherited from class java.lang.Object

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

Constructor Detail

ShortHammingFactory

public ShortHammingFactory(int ndims,
                           cern.jet.random.engine.MersenneTwister rng,
                           int bitsPerDim)

Construct a new factory using the given parameters.

Parameters:

ndims - The number of dimensions (i.e. length of the vector being hashed)

rng - A random number generator

bitsPerDim - The number of bits per dimension. If the data is packed, then this will be greater than zero, and internally a single bit will be sampled for computing the hash. If zero, then it is assumed that every element of the vector being hashed is either a zero or one.

Method Detail

create

public org.openimaj.lsh.functions.ShortHammingFactory.Function create()

Description copied from interface: HashFunctionFactory

Construct a new HashFunction.

Returns:

the new HashFunction

fvDistanceFunction

public ShortFVComparison fvDistanceFunction()

Specified by:

fvDistanceFunction in class ShortHashFunctionFactory