org.la4j.vector

Class SparseVector

java.lang.Object

org.la4j.Vector

org.la4j.vector.SparseVector

All Implemented Interfaces:

Iterable<Double>

Direct Known Subclasses:

CompressedVector

public abstract class SparseVector
extends Vector

A sparse vector. A vector represents an array of elements. It can be re-sized. A sparse data structure does not store blank elements, and instead just stores elements with values. A sparse data structure can be initialized with a large length but take up no storage until the space is filled with non-zero elements. However, there is a performance cost. Fetch/store operations take O(log n) time instead of the O(1) time of a dense data structure.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	cardinality

Fields inherited from class org.la4j.Vector

length

Constructor Summary

Constructors

Constructor and Description
SparseVector(int length)
SparseVector(int length, int cardinality)

Method Summary

Methods

Modifier and Type	Method and Description
Vector	add(double value) Adds given value (v) to this vector (X).
<T> T	apply(VectorMatrixOperation<T> operation, Matrix that) Pipes this vector to a given operation.
<T> T	apply(VectorOperation<T> operation) Pipes this vector to a given operation.
<T> T	apply(VectorVectorOperation<T> operation, Vector that) Pipes this vector to a given operation.
int	cardinality() Returns the cardinality (the number of non-zero elements) of this sparse vector.
double	density() Returns the density (non-zero elements divided by total elements) of this sparse vector.
void	eachNonZero(VectorProcedure procedure) Applies given procedure to each non-zero element of this vector.
protected void	ensureIndexIsInBounds(int i) Ensures the provided index is in the bounds of this SparseVector.
double	euclideanNorm() Calculates an Euclidean norm of this vector.
double	foldNonZero(VectorAccumulator accumulator) Folds non-zero elements of this vector with given accumulator.
static SparseVector	fromArray(double[] array) Creates a new SparseVector from the given array with compressing (copying) the underlying array.
static SparseVector	fromCollection(Collection<? extends Number> list) Creates new SparseVector from collection
static SparseVector	fromCSV(String csv) Parses SparseVector from the given CSV string.
static SparseVector	fromMap(Map<Integer,? extends Number> map, int length) Creates new SparseVector from given index-value map
static SparseVector	fromMatrixMarket(String mm) Parses SparseVector from the given Matrix Market string.
double	get(int i) Gets the specified element of this vector.
abstract double	getOrElse(int i, double defaultValue) Gets the specified element, or a defaultValue if there is no actual element at index i in this sparse vector.
int	hashCode() Calculates the hash-code of this vector.
double	infinityNorm() Calculates an Infinity norm of this vector.
boolean	isZeroAt(int i) Whether or not the specified element is zero.
double	manhattanNorm() Calculates a Manhattan norm of this vector.
double	max() Searches for the maximum value of the elements of this vector.
double	min() Searches for the minimum value of the elements of this vector.
Vector	multiply(double value) Multiplies this vector (X) by given value (v).
abstract boolean	nonZeroAt(int i) * Whether or not the specified element is not zero.
abstract VectorIterator	nonZeroIterator() Returns a non-zero vector iterator.
static SparseVector	random(int length, double density, Random random) Creates a constant SparseVector of the given length with the given value.
<T extends Vector> T	to(VectorFactory<T> factory) Converts this vector using the given factory.
Matrix	toColumnMatrix() Converts this vector to matrix with only one column.
Matrix	toDiagonalMatrix() Converts this vector to a diagonal matrix.
String	toMatrixMarket(NumberFormat formatter) Converts this vector into the string in Matrix Market format using the given formatter;
Matrix	toRowMatrix() Converts this vector to matrix with only one row.
static SparseVector	zero(int length) Creates a zero SparseVector of the given length.
static SparseVector	zero(int length, int capacity) Creates a zero SparseVector of the given length with the given capacity.

Methods inherited from class org.la4j.Vector

add, blank, blankOfLength, constant, copy, copyOfLength, divide, each, ensureLengthIsCorrect, equals, equals, fail, fold, hadamardProduct, innerProduct, is, iterator, length, mkString, mkString, multiply, non, norm, outerProduct, product, random, select, set, setAll, shuffle, slice, sliceLeft, sliceRight, subtract, subtract, sum, swapElements, toBinary, toCSV, toCSV, toDenseVector, toMatrixMarket, toSparseVector, toString, transform, unit, update, updateAt

Methods inherited from class java.lang.Object

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

Field Detail

cardinality

protected int cardinality

Constructor Detail

SparseVector

public SparseVector(int length)

SparseVector

public SparseVector(int length,
            int cardinality)

Method Detail

zero

public static SparseVector zero(int length)

Creates a zero SparseVector of the given length.

zero

public static SparseVector zero(int length,
                int capacity)

Creates a zero SparseVector of the given length with the given capacity.

random

public static SparseVector random(int length,
                  double density,
                  Random random)

Creates a constant SparseVector of the given length with the given value.

fromArray

public static SparseVector fromArray(double[] array)

Creates a new SparseVector from the given array with compressing (copying) the underlying array.

fromCSV

public static SparseVector fromCSV(String csv)

Parses SparseVector from the given CSV string.

Parameters:

csv - the CSV string representing a vector

Returns:

a parsed vector

fromMatrixMarket

public static SparseVector fromMatrixMarket(String mm)

Parses SparseVector from the given Matrix Market string.

Parameters:

mm - the string in Matrix Market format

Returns:

a parsed vector

fromCollection

public static SparseVector fromCollection(Collection<? extends Number> list)

Creates new SparseVector from collection

Parameters:

list - value list

Returns:

created vector

fromMap

public static SparseVector fromMap(Map<Integer,? extends Number> map,
                   int length)

Creates new SparseVector from given index-value map

Parameters:

map -

Returns:

cardinality

public int cardinality()

Returns the cardinality (the number of non-zero elements) of this sparse vector.

Returns:

the cardinality of this vector

density

public double density()

Returns the density (non-zero elements divided by total elements) of this sparse vector.

Returns:

the density of this vector

get

public double get(int i)

Description copied from class: Vector

Gets the specified element of this vector.

Specified by:

get in class Vector

Parameters:

i - element's index

Returns:

the element of this vector

getOrElse

public abstract double getOrElse(int i,
               double defaultValue)

Gets the specified element, or a defaultValue if there is no actual element at index i in this sparse vector.

Parameters:

i - the element's index

defaultValue - the default value

Returns:

the element of this vector or a default value

isZeroAt

public boolean isZeroAt(int i)

Whether or not the specified element is zero.

Parameters:

i - element's index

Returns:

true if specified element is zero, false otherwise

nonZeroAt

public abstract boolean nonZeroAt(int i)

* Whether or not the specified element is not zero.

Parameters:

i - element's index

Returns:

true if specified element is zero, false otherwise

foldNonZero

public double foldNonZero(VectorAccumulator accumulator)

Folds non-zero elements of this vector with given accumulator.

Parameters:

accumulator - the vector accumulator

Returns:

the accumulated value

eachNonZero

public void eachNonZero(VectorProcedure procedure)

Applies given procedure to each non-zero element of this vector.

Parameters:

procedure - the vector procedure

add

public Vector add(double value)

Description copied from class: Vector

Adds given value (v) to this vector (X).

Overrides:

add in class Vector

Parameters:

value - the right hand value for addition

Returns:

X + v

multiply

public Vector multiply(double value)

Description copied from class: Vector

Multiplies this vector (X) by given value (v).

Overrides:

multiply in class Vector

Parameters:

value - the right hand value for multiplication

Returns:

X * v

max

public double max()

Description copied from class: Vector

Searches for the maximum value of the elements of this vector.

Overrides:

max in class Vector

Returns:

the maximum value of this vector

min

public double min()

Description copied from class: Vector

Searches for the minimum value of the elements of this vector.

Overrides:

min in class Vector

Returns:

the minimum value of this vector

euclideanNorm

public double euclideanNorm()

Description copied from class: Vector

Calculates an Euclidean norm of this vector.

Overrides:

euclideanNorm in class Vector

Returns:

an Euclidean norm

manhattanNorm

public double manhattanNorm()

Description copied from class: Vector

Calculates a Manhattan norm of this vector.

Overrides:

manhattanNorm in class Vector

Returns:

a Manhattan norm

infinityNorm

public double infinityNorm()

Description copied from class: Vector

Calculates an Infinity norm of this vector.

Overrides:

infinityNorm in class Vector

Returns:

an Infinity norm

nonZeroIterator

public abstract VectorIterator nonZeroIterator()

Returns a non-zero vector iterator.

Returns:

a non-zero vector iterator

to

public <T extends Vector> T to(VectorFactory<T> factory)

Description copied from class: Vector

Converts this vector using the given factory.

Overrides:

to in class Vector

Type Parameters:

T - type of the result vector

Parameters:

factory - the factory that creates an output vector

Returns:

a converted vector

hashCode

public int hashCode()

Description copied from class: Vector

Calculates the hash-code of this vector.

Overrides:

hashCode in class Vector

apply

public <T> T apply(VectorOperation<T> operation)

Description copied from class: Vector

Pipes this vector to a given operation.

Specified by:

apply in class Vector

Type Parameters:

T - the result type

Parameters:

operation - the vector operation (an operation that take vector and returns T)

Returns:

the result of an operation applied to this vector

apply

public <T> T apply(VectorVectorOperation<T> operation,
          Vector that)

Description copied from class: Vector

Pipes this vector to a given operation.

Specified by:

apply in class Vector

Type Parameters:

T - the result type

Parameters:

operation - the vector-vector operation (an operation that takes two vectors and returns T)

that - the right hand vector for the given operation

Returns:

the result of an operation applied to this and that vector

apply

public <T> T apply(VectorMatrixOperation<T> operation,
          Matrix that)

Description copied from class: Vector

Pipes this vector to a given operation.

Specified by:

apply in class Vector

Type Parameters:

T - the result type

Parameters:

operation - the vector-matrix operation (an operation that takes vector and matrix and returns T)

that - the right hand matrix for the given operation

Returns:

the result of an operation applied to this vector and that matrix

toRowMatrix

public Matrix toRowMatrix()

Description copied from class: Vector

Converts this vector to matrix with only one row.

Specified by:

toRowMatrix in class Vector

Returns:

the row matrix

toColumnMatrix

public Matrix toColumnMatrix()

Description copied from class: Vector

Converts this vector to matrix with only one column.

Specified by:

toColumnMatrix in class Vector

Returns:

the column matrix

toDiagonalMatrix

public Matrix toDiagonalMatrix()

Description copied from class: Vector

Converts this vector to a diagonal matrix.

Specified by:

toDiagonalMatrix in class Vector

Returns:

a diagonal matrix

toMatrixMarket

public String toMatrixMarket(NumberFormat formatter)

Description copied from class: Vector

Converts this vector into the string in Matrix Market format using the given formatter;

Specified by:

toMatrixMarket in class Vector

Parameters:

formatter - the number formater

Returns:

a Matrix Market string representing this vector

ensureIndexIsInBounds

protected void ensureIndexIsInBounds(int i)

Ensures the provided index is in the bounds of this SparseVector.

Parameters:

i - The index to check.