edu.ucla.sspace.vector

Class SparseHashDoubleVector

java.lang.Object

edu.ucla.sspace.vector.SparseHashDoubleVector

All Implemented Interfaces:

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

public class SparseHashDoubleVector
extends Object
implements SparseDoubleVector, Serializable

A SparseVector implementation backed by a Map. This provides amoritized constant time access to all get and set operations, while using more space than the CompactSparseVector or AmortizedSparseVector classes.

See SparseHashArray for implementation details.

Author:

David Jurgens

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SparseHashDoubleVector(double[] values) Creates a new vector using the non-zero values of the specified array.
SparseHashDoubleVector(DoubleVector values)
SparseHashDoubleVector(int length) Creates a new vector of the specified length

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	get(int index) Returns the value of this vector at the given index.
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.
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

SparseHashDoubleVector

public SparseHashDoubleVector(int length)

Creates a new vector of the specified length

Parameters:

length - the length of this vector

SparseHashDoubleVector

public SparseHashDoubleVector(double[] values)

Creates a new vector using the non-zero values of the specified array. The created vector contains no references to the provided array, so changes to either will not be reflected in the other.

Parameters:

values - the intial values for this vector to have

SparseHashDoubleVector

public SparseHashDoubleVector(DoubleVector values)

Method Detail

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.

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.

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.

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.

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.

magnitude

public double magnitude()

Returns the magnitude of this vector

Specified by:

magnitude in interface Vector<Double>

getNonZeroIndices

public int[] getNonZeroIndices()

Returns all the indices whose values are non-zero

Specified by:

getNonZeroIndices in interface SparseVector<Double>