edu.ucla.sspace.vector

Class AtomicSparseVector

java.lang.Object

edu.ucla.sspace.vector.AtomicSparseVector

All Implemented Interfaces:

DoubleVector, SparseDoubleVector, SparseVector<Double>, Vector<Double>, Serializable

public class AtomicSparseVector
extends Object
implements SparseDoubleVector, Serializable

A decorator of a Vector which provides atomic concurrent access to another Vector. This allows all reads to be done concurrently, while limiting to writing to only one thread at a time. This does not provide a specific implementation of a Vector, allowing any Vector implementation to be made atomic.

Author:

David Jurgens, Keith Stevens

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AtomicSparseVector(SparseDoubleVector v) Creates a new AtomicSparseVector decorating an already existing Vector.

Method Summary

Methods

Modifier and Type	Method and Description
double	add(int index, double delta) Changes the value in this vector by a specified amount (optional operation).
double	addAndGet(int index, double delta)
double	get(int index) Returns the value of this vector at the given index.
double	getAndAdd(int index, double delta)
int[]	getNonZeroIndices() Returns all the indices whose values are non-zero
Double	getValue(int index) Return the value of the vector at the given index as a Number.
SparseDoubleVector	getVector() Returns the SparseDoubleVector that backs this instance.
int	length() Return the size of the Vector.
double	magnitude() Returns the magnitude of this vector
void	set(int index, double value) Sets the length in this vector (optional operation).
void	set(int index, Number value) Set the value in the vector (optional operation).
double[]	toArray() Returns a double array representing this vector.

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.ucla.sspace.vector.Vector

equals, hashCode

Constructor Detail

AtomicSparseVector

public AtomicSparseVector(SparseDoubleVector v)

Creates a new AtomicSparseVector decorating an already existing Vector.

Parameters:

v - The vector to decorate.

Method Detail

addAndGet

public double addAndGet(int index,
               double delta)

getAndAdd

public double getAndAdd(int index,
               double delta)

add

public double add(int index,
         double delta)

Changes the value in this vector by a specified amount (optional operation). If there is not a value set at index, delta should be set to the actual value.

Specified by:

add in interface DoubleVector

Parameters:

index - index to change.

delta - the amount to change by.

Returns:

the resulting value at the index

get

public double get(int index)

Returns the value of this vector at the given index.

Specified by:

get in interface DoubleVector

Parameters:

index - index to retrieve.

Returns:

value at index.

getNonZeroIndices

public int[] getNonZeroIndices()

Returns all the indices whose values are non-zero

Specified by:

getNonZeroIndices in interface SparseVector<Double>

getValue

public Double getValue(int index)

Return the value of the vector at the given index as a Number.

Specified by:

getValue in interface DoubleVector

Specified by:

getValue in interface Vector<Double>

Parameters:

index - index to retrieve.

Returns:

value at index.

getVector

public SparseDoubleVector getVector()

Returns the SparseDoubleVector that backs this instance.

magnitude

public double magnitude()

Returns the magnitude of this vector

Specified by:

magnitude in interface Vector<Double>

set

public void set(int index,
       double value)

Sets the length in this vector (optional operation).

Specified by:

set in interface DoubleVector

Parameters:

index - index to set.

value - value to set in the vector.

set

public void set(int index,
       Number value)

Set the value in the vector (optional operation).

Specified by:

set in interface Vector<Double>

Parameters:

index - index to set.

value - value to set in the vector.

toArray

public double[] toArray()

Returns a double array representing this vector. The returned array will be "safe" in that no changes to the array will be reflected in the vector, and likewise for changes to to the vector. The caller is thus free to modify the returned array.

Specified by:

toArray in interface DoubleVector

Returns:

a double array of this vector.

length

public int length()

Return the size of the Vector.

Specified by:

length in interface Vector<Double>

Returns:

size of the vector.