info.debatty.java.utils

Class SparseDoubleVector

java.lang.Object

info.debatty.java.utils.SparseDoubleVector

All Implemented Interfaces:

Serializable

public class SparseDoubleVector
extends Object
implements Serializable

Sparse vector of double, implemented using two arrays

Author:

Thibault Debatty

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	keys
protected int	size
protected double[]	values

Constructor Summary

Constructors

Constructor and Description
SparseDoubleVector()
SparseDoubleVector(double[] array)
SparseDoubleVector(HashMap<Integer,Double> hashmap)
SparseDoubleVector(int size)

Method Summary

Methods

Modifier and Type	Method and Description
double	cosineSimilarity(SparseDoubleVector other)
double	dotProduct(double[] other)
double	dotProduct(SparseDoubleVector other)
int	intersection(SparseDoubleVector other)
double	jaccard(SparseDoubleVector other) Computes and return the Jaccard index with other SparseVector.
double	norm() Compute and return the L2 norm of the vector
double	qgram(SparseDoubleVector other) Compute and return the qgram similarity with other vector.
void	sampleDIMSUM(double threshold, int count, int size)
int	size() Return the number of (non-zero) elements in this vector.
double[]	toArray(int size)
String	toString()
int	union(SparseDoubleVector other)

Methods inherited from class java.lang.Object

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

Field Detail

keys

protected int[] keys

values

protected double[] values

size

protected int size

Constructor Detail

SparseDoubleVector

public SparseDoubleVector(int size)

SparseDoubleVector

public SparseDoubleVector()

SparseDoubleVector

public SparseDoubleVector(HashMap<Integer,Double> hashmap)

SparseDoubleVector

public SparseDoubleVector(double[] array)

Parameters:

array -

Method Detail

dotProduct

public double dotProduct(SparseDoubleVector other)

Parameters:

other -

Returns:

dotProduct

public double dotProduct(double[] other)

jaccard

public double jaccard(SparseDoubleVector other)

Computes and return the Jaccard index with other SparseVector. |A inter B| / |A union B| It is actually computed as |A inter B| / (|A| +|B| - | A inter B|) using a single loop over A and B

Parameters:

other -

Returns:

union

public int union(SparseDoubleVector other)

Parameters:

other -

Returns:

intersection

public int intersection(SparseDoubleVector other)

Parameters:

other -

Returns:

toString

public String toString()

Overrides:

toString in class Object

qgram

public double qgram(SparseDoubleVector other)

Compute and return the qgram similarity with other vector. Sum(|a_i - b_i|)

Parameters:

other -

Returns:

size

public int size()

Return the number of (non-zero) elements in this vector.

Returns:

norm

public double norm()

Compute and return the L2 norm of the vector

Returns:

cosineSimilarity

public double cosineSimilarity(SparseDoubleVector other)

Parameters:

other -

Returns:

sampleDIMSUM

public void sampleDIMSUM(double threshold,
                int count,
                int size)

toArray

public double[] toArray(int size)