info.debatty.java.lsh

Class LSHMinHash

java.lang.Object

info.debatty.java.lsh.LSH

info.debatty.java.lsh.LSHMinHash

All Implemented Interfaces:

Serializable

public class LSHMinHash
extends LSH

Author:

Thibault Debatty

See Also:

Serialized Form

Field Summary

Fields inherited from class info.debatty.java.lsh.LSH

LARGE_PRIME

Constructor Summary

Constructors

Constructor and Description
LSHMinHash(int s, int b, int n) Instantiates a LSH instance that internally uses MinHash, with s stages (or bands) and b buckets (per stage), for sets out of a dictionary of n elements.
LSHMinHash(int s, int b, int n, long seed) Instantiates a LSH instance that internally uses MinHash, with s stages (or bands) and b buckets (per stage), for sets out of a dictionary of n elements.

Method Summary

Modifier and Type	Method and Description
long[][]	getCoefficients() Get the coefficients used by internal hashing functions.
int[]	hash(boolean[] vector) Bin this vector to corresponding buckets.

Methods inherited from class info.debatty.java.lsh.LSH

hashSignature, hashSignature

Methods inherited from class java.lang.Object

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

Constructor Detail

LSHMinHash

public LSHMinHash(int s,
                  int b,
                  int n)

Instantiates a LSH instance that internally uses MinHash, with s stages (or bands) and b buckets (per stage), for sets out of a dictionary of n elements. Attention: the number of buckets should be chosen such that we have at least 100 items per bucket.

Parameters:

s - stages

b - buckets (per stage)

n - dictionary size

LSHMinHash

public LSHMinHash(int s,
                  int b,
                  int n,
                  long seed)

Instantiates a LSH instance that internally uses MinHash, with s stages (or bands) and b buckets (per stage), for sets out of a dictionary of n elements. Attention: the number of buckets should be chosen such that we have at least 100 items per bucket.

Parameters:

s - stages

b - buckets (per stage)

n - dictionary size

seed - random number generator seed. using the same value will guarantee identical hashes across object instantiations

Method Detail

hash

public final int[] hash(boolean[] vector)

Bin this vector to corresponding buckets.

Parameters:

vector -

Returns:

getCoefficients

public final long[][] getCoefficients()

Get the coefficients used by internal hashing functions.

Returns: