Package it.unimi.dsi.law.vector

Class ImmutableSparseVector

java.lang.Object

it.unimi.dsi.law.vector.Vector

it.unimi.dsi.law.vector.ImmutableSparseVector

All Implemented Interfaces:

Serializable

public class ImmutableSparseVector
extends Vector

An immutable implementation of Vector optimized for sparse vectors.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
int[]	index	An arrays containing the indexes of the vector values.
int	nonZero	The number of non-zero entry in this vector.
double[]	value	An arrays containing vector values.

Fields inherited from class it.unimi.dsi.law.vector.Vector

ell1norm, ell2norm, id, INVALID_ID, INVALID_NORM, size

Method Summary

Modifier and Type	Method	Description
void	add(double alpha, Vector v)	Adds values in vector v scaled by alpha to this vector.
double	dotProduct(Vector v)	Returns the dot product between v and this vector.
double	ell1Norm()	Returns the l1 norm of this vector.
double	ell2Norm()	Returns the l2 norm of this vector.
double	euclideanDistance(Vector v)	Returns the euclidean distance between v and this vector.
double	get(int idx)	Gets the value at index idx.
static ImmutableSparseVector	getInstance(double[] value, double threshold, int id)	Returns an instance containing all the values of a given array larger or smaller of a given threshold.
static ImmutableSparseVector	getInstance(int[] index, double[] value, int size, double threshold, int id)	Returns an instance containing all the values of a given array larger than a given threshold.
static ImmutableSparseVector	getInstance(int size, double[] value, int[] index, int id)	Returns an instance of given size from an array of values.
static ImmutableSparseVector	getInstance(Vector v, double threshold, int id)	Returns an instance containing all the values of a given vector larger or smaller of a given threshold.
void	scale(double alpha)	Scale values in this vector by a value alpha.
void	set(int idx, double val)	Sets the value val at index idx.
void	zero()	Reset (to zero) this vector.

Methods inherited from class it.unimi.dsi.law.vector.Vector

isMutable

Methods inherited from class java.lang.Object

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

Field Details

value

public final double[] value

An arrays containing vector values.

index

public final int[] index

An arrays containing the indexes of the vector values.

nonZero

public final int nonZero

The number of non-zero entry in this vector.

Method Details

getInstance

public static ImmutableSparseVector getInstance(int size,
double[] value,
int[] index,
int id)

Returns an instance of given size from an array of values.

Parameters:

size - the size.

value - the value.

index - the index.

id - the id of description of this vector.

Returns:

an immutable vector.

getInstance

public static ImmutableSparseVector getInstance(Vector v,
double threshold,
int id)

Returns an instance containing all the values of a given vector larger or smaller of a given threshold. The vector will have size equal to the vector length.

Parameters:

v - the vector.

threshold - the threshold.

id - the id of description of this vector.

Returns:

an immutable vector

getInstance

public static ImmutableSparseVector getInstance(double[] value,
double threshold,
int id)

Returns an instance containing all the values of a given array larger or smaller of a given threshold. The vector will have size equal to the array length.

Parameters:

value - tha array of double.

threshold - the threshold.

id - the id of description associated with this vector.

Returns:

an immutable vector.

getInstance

public static ImmutableSparseVector getInstance(int[] index,
double[] value,
int size,
double threshold,
int id)

Returns an instance containing all the values of a given array larger than a given threshold. The vector will have the given size

Parameters:

value - tha array of double.

threshold - the threshold.

id - the id of description associated with this vector.

Returns:

an immutable vector.

set

public void set(int idx,
double val)

Description copied from class: Vector

Sets the value val at index idx.

Specified by:

set in class Vector

Parameters:

idx - the index.

val - the value.

get

public double get(int idx)

Description copied from class: Vector

Gets the value at index idx.

Specified by:

get in class Vector

Parameters:

idx - the index.

Returns:

the value at index idx.

add

public void add(double alpha,
Vector v)

Description copied from class: Vector

Adds values in vector v scaled by alpha to this vector.

Overrides:

add in class Vector

Parameters:

alpha - the scaling factor.

v - the vector to add.

scale

public void scale(double alpha)

Description copied from class: Vector

Scale values in this vector by a value alpha.

Overrides:

scale in class Vector

Parameters:

alpha - the scaling factor

zero

public void zero()

Description copied from class: Vector

Reset (to zero) this vector.

Overrides:

zero in class Vector

dotProduct

public double dotProduct(Vector v)

Description copied from class: Vector

Returns the dot product between v and this vector.

Overrides:

dotProduct in class Vector

Parameters:

v - the vector.

Returns:

the dot product.

euclideanDistance

public double euclideanDistance(Vector v)

Description copied from class: Vector

Returns the euclidean distance between v and this vector.

Overrides:

euclideanDistance in class Vector

Parameters:

v - the vector.

Returns:

the euclidean distance.

ell2Norm

public double ell2Norm()

Description copied from class: Vector

Returns the l₂ norm of this vector.

Overrides:

ell2Norm in class Vector

Returns:

the l₂ norm.

ell1Norm

public double ell1Norm()

Description copied from class: Vector

Returns the l₁ norm of this vector.

Overrides:

ell1Norm in class Vector