JSci.maths
Class DoubleSparseVector

java.lang.Object
  JSci.maths.MathVector
      JSci.maths.DoubleVector
          JSci.maths.DoubleSparseVector

All Implemented Interfaces:

java.io.Serializable, BanachSpace.Member, Module.Member, VectorSpace.Member, AbelianGroup.Member, Member

public final class DoubleSparseVector
extends DoubleVector

The DoubleSparseVector class encapsulates sparse vectors. Uses Morse-coding.

Author:

Daniel Lemire, Alain Beliveau

See Also:

Serialized Form

Field Summary

protected static int

SPARSE Storage format identifier.

Fields inherited from class JSci.maths.DoubleVector

ARRAY_1D, vector

Fields inherited from class JSci.maths.MathVector

CLASS_SPECIFIC, N, storageFormat

Constructor Summary

DoubleSparseVector(double[] array)
Constructs a vector from an array.

DoubleSparseVector(int dim)
Constructs an empty vector.

Method Summary

DoubleSparseVector	add(DoubleSparseVector v) Returns the addition of this vector and another.
DoubleVector	add(DoubleVector v) Returns the addition of this vector and another.
boolean	equals(java.lang.Object a) Compares two vectors for equality.
protected void	finalize() Finalize.
double	getComponent(int n) Returns a component of this vector.
DoubleVector	mapComponents(Mapping f) Applies a function on all the vector components.
double	mass() Returns the mass.
double	norm() Returns the l2-norm (magnitude).
void	normalize() Makes the norm of this vector equal to 1.
DoubleVector	scalarDivide(double x) Returns the division of this vector by a scalar.
DoubleVector	scalarMultiply(double x) Returns the multiplication of this vector by a scalar.
double	scalarProduct(DoubleSparseVector v) Returns the scalar product of this vector and another.
double	scalarProduct(DoubleVector v) Returns the scalar product of this vector and another.
void	setComponent(int n, double x) Sets the value of a component of this vector.
DoubleSparseVector	subtract(DoubleSparseVector v) Returns the subtraction of this vector by another.
DoubleVector	subtract(DoubleVector v) Returns the subtraction of this vector by another.
double	sumSquares() Returns the sum of the squares of the components.
DoubleSparseMatrix	tensorProduct(DoubleSparseVector v) Returns the tensor product of this vector and another.
java.lang.String	toString() Returns a comma delimited string representing the value of this vector.

Methods inherited from class JSci.maths.DoubleVector

add, hashCode, infNorm, negate, norm, scalarDivide, scalarMultiply, subtract, toComplexVector, toIntegerVector

Methods inherited from class JSci.maths.MathVector

dimension, getInvalidComponentMsg

Methods inherited from class java.lang.Object

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

Field Detail

SPARSE

protected static final int SPARSE

Storage format identifier.

See Also:

Constant Field Values

Constructor Detail

DoubleSparseVector

public DoubleSparseVector(int dim)

Constructs an empty vector.

Parameters:

dim - the dimension of the vector.

DoubleSparseVector

public DoubleSparseVector(double[] array)

Constructs a vector from an array.

Method Detail

finalize

protected void finalize()
                 throws java.lang.Throwable

Finalize.

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable - Any that occur.

equals

public boolean equals(java.lang.Object a)

Compares two vectors for equality.

Overrides:

equals in class DoubleVector

Parameters:

a - a double sparse vector

toString

public java.lang.String toString()

Returns a comma delimited string representing the value of this vector.

Overrides:

toString in class DoubleVector

getComponent

public double getComponent(int n)

Returns a component of this vector.

Overrides:

getComponent in class DoubleVector

Parameters:

n - index of the vector component

Throws:

VectorDimensionException - If attempting to access an invalid component.

setComponent

public void setComponent(int n,
                         double x)

Sets the value of a component of this vector.

Overrides:

setComponent in class DoubleVector

Parameters:

n - index of the vector component

x - a number

Throws:

VectorDimensionException - If attempting to access an invalid component.

norm

public double norm()

Returns the l²-norm (magnitude).

Specified by:

norm in interface BanachSpace.Member

Overrides:

norm in class DoubleVector

normalize

public void normalize()

Makes the norm of this vector equal to 1.

Overrides:

normalize in class DoubleVector

sumSquares

public double sumSquares()

Returns the sum of the squares of the components.

mass

public double mass()

Returns the mass.

add

public DoubleVector add(DoubleVector v)

Returns the addition of this vector and another.

Overrides:

add in class DoubleVector

Parameters:

v - a double vector

Throws:

VectorDimensionException - If the vectors are different sizes.

add

public DoubleSparseVector add(DoubleSparseVector v)

Returns the addition of this vector and another.

Parameters:

v - a double sparse vector

Throws:

VectorDimensionException - If the vectors are different sizes.

subtract

public DoubleVector subtract(DoubleVector v)

Returns the subtraction of this vector by another.

Overrides:

subtract in class DoubleVector

Parameters:

v - a double vector

Throws:

VectorDimensionException - If the vectors are different sizes.

subtract

public DoubleSparseVector subtract(DoubleSparseVector v)

Returns the subtraction of this vector by another.

Parameters:

v - a double sparse vector

Throws:

VectorDimensionException - If the vectors are different sizes.

scalarMultiply

public DoubleVector scalarMultiply(double x)

Returns the multiplication of this vector by a scalar.

Overrides:

scalarMultiply in class DoubleVector

Parameters:

x - a double

scalarDivide

public DoubleVector scalarDivide(double x)

Returns the division of this vector by a scalar.

Overrides:

scalarDivide in class DoubleVector

Parameters:

x - a double

Throws:

java.lang.ArithmeticException - If divide by zero.

scalarProduct

public double scalarProduct(DoubleVector v)

Returns the scalar product of this vector and another.

Overrides:

scalarProduct in class DoubleVector

Parameters:

v - a double vector

Throws:

VectorDimensionException - If the vectors are different sizes.

scalarProduct

public double scalarProduct(DoubleSparseVector v)

Returns the scalar product of this vector and another.

Parameters:

v - a double sparse vector

Throws:

VectorDimensionException - If the vectors are different sizes.

tensorProduct

public DoubleSparseMatrix tensorProduct(DoubleSparseVector v)

Returns the tensor product of this vector and another.

mapComponents

public DoubleVector mapComponents(Mapping f)

Applies a function on all the vector components.

Overrides:

mapComponents in class DoubleVector

Parameters:

f - a user-defined function

Returns:

a double sparse vector