it.uniroma2.sag.kelp.data.representation.vector

Class DenseVector

java.lang.Object

it.uniroma2.sag.kelp.data.representation.vector.DenseVector

All Implemented Interfaces:

Normalizable, Representation, Vector, Serializable

public class DenseVector
extends Object
implements Vector

Dense Feature Vector.
It uses EJML to guarantee a very fast computation

Author:

Simone Filice

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	SEPARATOR

Constructor Summary

Constructors

Constructor and Description
DenseVector() Empty constructor necessary for making RepresentationFactory support this implementation.
DenseVector(org.ejml.data.DenseMatrix64F featureVector) Initializing constructor.
DenseVector(double[] featureVector) Initializing constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(float coeff, float vectorCoeff, Vector vector) Add a vector multiplied by vectorCoeff to this vector multiplied by
void	add(float coeff, Vector vector) Add a vector multiplied by coeff to this vector
void	add(Vector vector) Add a vector to this vector
DenseVector	copyVector() Returns a copy of this vector.
void	diff(DenseVector vector)
boolean	equals(Object featureVector)
float	euclideanDistance(Vector vector) Returns the euclidean distance between this vector and vector
Map<Object,Number>	getActiveFeatures() Returns a map containing all the non-zero features
double	getFeatureValue(int featureIndex) Returns the feature value of the featureIndex-th element
float	getFeatureValue(Object featureIdentifier) Returns the value of the feature identified with featureIdentifier
org.ejml.data.DenseMatrix64F	getFeatureValues() Returns the feature values in the EJML format
int	getNumberOfFeatures() Returns the number of featuresValues
float	getSquaredNorm() Returns the squared norm of this vector
String	getTextFromData() Returns a textual representation of the data stored in this representation
DenseVector	getZeroVector() Returns a vector whose values are all 0.
float	innerProduct(Vector vector) Returns the dot product between this vector and vector
boolean	isCompatible(Representation rep) Evaluates whether a representation is compatible with this one, e.g.., they have same type and pass additional checks that are type-dependent
void	normalize() Scales the representation in order to have a unit norm in the explicit feature space
void	pointWiseProduct(Vector vector) Compute the point-wise product of this vector with the one in vector.
void	scale(float coeff) Multiplies each element of this representation by coeff
void	setDataFromText(String representationDescription) Set the values of the vectors according to the input text, which is expected to be a sequence of numbers separated by a white space, or a comma, or a semicolon
void	setFeatureValue(Object featureIdentifier, float value) Assigns value to the feature identified by featureIdentifier
void	setFeatureValues(org.ejml.data.DenseMatrix64F featureVector) Sets the feature values.
void	setFeatureValues(double[] featureValues) Sets the feature values.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

SEPARATOR

public static final String SEPARATOR

See Also:

Constant Field Values

Constructor Detail

DenseVector

public DenseVector()

Empty constructor necessary for making RepresentationFactory support this implementation.

Parameters:

featureVector - is an array of feature values

DenseVector

public DenseVector(double[] featureVector)

Initializing constructor.

Parameters:

featureVector - is an array of feature values

DenseVector

public DenseVector(org.ejml.data.DenseMatrix64F featureVector)

Initializing constructor.

Parameters:

featureVector - is an array of feature values in the EJML format

Method Detail

setDataFromText

public void setDataFromText(String representationDescription)

Set the values of the vectors according to the input text, which is expected to be a sequence of numbers separated by a white space, or a comma, or a semicolon

Specified by:

setDataFromText in interface Representation

Parameters:

representationDescription - the textual description

setFeatureValues

public void setFeatureValues(double[] featureValues)

Sets the feature values.

Parameters:

featureValues - is an array of feature values

setFeatureValues

public void setFeatureValues(org.ejml.data.DenseMatrix64F featureVector)

Sets the feature values.

Parameters:

featureVector - is an array of feature values in the EJML format

getFeatureValues

public org.ejml.data.DenseMatrix64F getFeatureValues()

Returns the feature values in the EJML format

Returns:

the feature values

getFeatureValue

public double getFeatureValue(int featureIndex)

Returns the feature value of the featureIndex-th element

Parameters:

featureIndex - the index of the feature whose value must be returned

Returns:

the value of the feature

getNumberOfFeatures

public int getNumberOfFeatures()

Returns the number of featuresValues

Returns:

the number of featuresValues

equals

public boolean equals(Object featureVector)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

normalize

public void normalize()

Description copied from interface: Normalizable

Scales the representation in order to have a unit norm in the explicit feature space

Specified by:

normalize in interface Normalizable

innerProduct

public float innerProduct(Vector vector)

Description copied from interface: Vector

Returns the dot product between this vector and vector

Specified by:

innerProduct in interface Vector

Returns:

the dot product

pointWiseProduct

public void pointWiseProduct(Vector vector)

Description copied from interface: Vector

Compute the point-wise product of this vector with the one in vector.

Specified by:

pointWiseProduct in interface Vector

Parameters:

vector - the vector used for the point-wise product

scale

public void scale(float coeff)

Description copied from interface: Normalizable

Multiplies each element of this representation by coeff

Specified by:

scale in interface Normalizable

Parameters:

coeff - the scaling factor

add

public void add(Vector vector)

Description copied from interface: Vector

Add a vector to this vector

Specified by:

add in interface Vector

Parameters:

vector - the vector to be added

diff

public void diff(DenseVector vector)

add

public void add(float coeff,
       Vector vector)

Description copied from interface: Vector

Add a vector multiplied by coeff to this vector

Specified by:

add in interface Vector

Parameters:

coeff - the vector coefficient

vector - the vector to be added

euclideanDistance

public float euclideanDistance(Vector vector)
                        throws VectorOperationException

Description copied from interface: Vector

Returns the euclidean distance between this vector and vector

Specified by:

euclideanDistance in interface Vector

Returns:

the euclidead distance

Throws:

VectorOperationException

add

public void add(float coeff,
       float vectorCoeff,
       Vector vector)

Description copied from interface: Vector

Add a vector multiplied by vectorCoeff to this vector multiplied by

Specified by:

add in interface Vector

Parameters:

coeff - the coefficient of this vector

vectorCoeff - the vector coefficient

vector - the vector to be added

getZeroVector

public DenseVector getZeroVector()

Description copied from interface: Vector

Returns a vector whose values are all 0. The returned vector has the same dimensions of this

Specified by:

getZeroVector in interface Vector

Returns:

a zero vector

getTextFromData

public String getTextFromData()

Description copied from interface: Representation

Returns a textual representation of the data stored in this representation

Specified by:

getTextFromData in interface Representation

Returns:

a textual representation of the data stored in this representation

getSquaredNorm

public float getSquaredNorm()

Description copied from interface: Normalizable

Returns the squared norm of this vector

Specified by:

getSquaredNorm in interface Normalizable

Returns:

the squared norm

getActiveFeatures

public Map<Object,Number> getActiveFeatures()

Description copied from interface: Vector

Returns a map containing all the non-zero features

Specified by:

getActiveFeatures in interface Vector

Returns:

the non zero features

copyVector

public DenseVector copyVector()

Description copied from interface: Vector

Returns a copy of this vector.

Specified by:

copyVector in interface Vector

Returns:

Vector

setFeatureValue

public void setFeatureValue(Object featureIdentifier,
                   float value)

Description copied from interface: Vector

Assigns value to the feature identified by featureIdentifier

NOTE: this method could be not the most efficient to set a feature value. Actual implementations of the Vector class may provide faster methods using their specific type to identify features (instead of a generic Object)

Specified by:

setFeatureValue in interface Vector

Parameters:

featureIdentifier - the identifier of the feature

value - the value of the feature

getFeatureValue

public float getFeatureValue(Object featureIdentifier)

Description copied from interface: Vector

Returns the value of the feature identified with featureIdentifier

NOTE: this method could be not the most efficient to get a feature value. Actual implementations of the Vector class may provide faster methods using their specific type to identify features (instead of a generic Object)

Specified by:

getFeatureValue in interface Vector

Returns:

the value of the feature

isCompatible

public boolean isCompatible(Representation rep)

Description copied from interface: Representation

Evaluates whether a representation is compatible with this one, e.g.., they have same type and pass additional checks that are type-dependent

Specified by:

isCompatible in interface Representation

Parameters:

rep - the representation to be compared with this one

Returns:

whether this representation is compatible with the input one