jnisvmlight
Class FeatureVector

java.lang.Object
  jnisvmlight.FeatureVector

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

LabeledFeatureVector

public class FeatureVector
extends java.lang.Object
implements java.io.Serializable

A feature vector. Features are dimension-value pairs. This class implements a simple dictionary data structure to map dimensions onto their values. Note that for convenience, features do not have be sorted according to their dimensions at this point. The SVMLightTrainer class has an option for sorting input vectors prior to training.

See Also:

Serialized Form

Field Summary

protected int[]	m_dims
protected double[]	m_vals

Constructor Summary

FeatureVector(int size)

FeatureVector(int[] dims, double[] vals)

Method Summary

double	getCosine(FeatureVector v) Returns the cosine similarity between two feature vectors.
int	getDimAt(int index)
double	getL1Norm() Returns the linear norm factor of this vector's values (i.e., the sum of it's values).
double	getL2Norm() Returns the L2 norm factor of this vector's values.
double	getValueAt(int index)
void	normalizeL1() Performs a linear normalization to the value 1.
void	normalizeL1(double norm) Performs a linear normalization to the given norm value.
void	normalizeL2() Performs an L2 normalization to the value 1.
void	setFeatures(int[] dims, double[] vals)
int	size()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

m_dims

protected int[] m_dims

m_vals

protected double[] m_vals

Constructor Detail

FeatureVector

public FeatureVector(int size)

FeatureVector

public FeatureVector(int[] dims,
                     double[] vals)

Method Detail

getCosine

public double getCosine(FeatureVector v)

Returns the cosine similarity between two feature vectors.

getDimAt

public int getDimAt(int index)

getL1Norm

public double getL1Norm()

Returns the linear norm factor of this vector's values (i.e., the sum of it's values).

getL2Norm

public double getL2Norm()

Returns the L2 norm factor of this vector's values.

getValueAt

public double getValueAt(int index)

normalizeL1

public void normalizeL1()

Performs a linear normalization to the value 1.

normalizeL1

public void normalizeL1(double norm)

Performs a linear normalization to the given norm value.

normalizeL2

public void normalizeL2()

Performs an L2 normalization to the value 1.

setFeatures

public void setFeatures(int[] dims,
                        double[] vals)

size

public int size()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object