scpsolver.util
Class SparseVector

java.lang.Object
  scpsolver.util.SparseVector

All Implemented Interfaces:

Matrix

public class SparseVector
extends java.lang.Object
implements Matrix

Implementation of a sparse vector

Author:

planatsc

Constructor Summary

SparseVector(double[] x)
Creates a new vector with entries taken from the array

SparseVector(int[] index, double[] data)

SparseVector(int size, int nonzerosize)
Constructs a new SparseVector of a given size and with a given starting capacity.

SparseVector(Matrix c)
Copies the matrix c.

SparseVector(SparseVector v)
Copy-constructor for the SparseVector

Method Summary

SparseVector	add(SparseVector v) Adds two sparse vectors
SparseVector	clone() Creates a deep copy of the vector
double	dot(double[] ydata) Calculates the dot product of this vector and the vector y
double	dot(SparseVector y) Calculates the dot product (or scalar product, inner product) of two vectors
double	dotdumb(SparseVector y) Calculates the dot product of this vector and the vector y
boolean	equals(java.lang.Object o) Compares two vectors.
boolean	equals(SparseVector v) Compares two SparseVectors
double[]	get() Returns the vector as a double array
double	get(int index) Gets the value at index inpired by http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ressim/mtj/src/no/uib/cipr/matrix/sparse/SparseVector.java?
double	get(int row, int column) Gets the value of the vector at the position donated by row and column.
int	getColNum() Returns the number of columns of the vector.
double[]	getData()
int[]	getIndex()
int	getIndex(int ind) Sets the index of a sparse vector inpired by http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ressim/mtj/src/no/uib/cipr/matrix/sparse/SparseVector.java?
NonZeroElementIterator	getNonZeroElementIterator()
int	getRowNum() Returns the number of rows of the vector.
int	getSize()
int	getUsed()
void	grow(int newsize, boolean bottom) Grows or shrinks the vector to the given size
void	grow(SparseVector v) Grows a vector with another vector
static void	main(java.lang.String[] args)
SparseVector	plus(Matrix y) Adds a second vector to the vector
void	set(int in, double value) Sets the entry of the vector to a given value
void	set(int row, int column, double value) Sets a certain entry of the vector to the given value.
void	setData(double[] data)
void	setIndex(int[] index)
void	setSize(int size)
void	setUsed(int used)
SparseVector	times(double c) Multiplies the vector with a scalar
Matrix	times(Matrix multiplier) Multiplies the vector with a matrix
java.lang.String	toString() String representation of this sparse vector.
Matrix	transpose() Transposes a vector

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

SparseVector

public SparseVector(int size,
                    int nonzerosize)

Constructs a new SparseVector of a given size and with a given starting capacity.

Parameters:

size - The actual size of the vector

nonzerosize - The starting capacity of the vector

SparseVector

public SparseVector(SparseVector v)

Copy-constructor for the SparseVector

Parameters:

v - The vector to be copied

SparseVector

public SparseVector(double[] x)

Creates a new vector with entries taken from the array

Parameters:

x - The entries of the new vector

SparseVector

public SparseVector(int[] index,
                    double[] data)

SparseVector

public SparseVector(Matrix c)

Copies the matrix c. Attention: this may only work if the matrix is a nx1 or a 1xn matrix.

Parameters:

c - The matrix to be copied

Method Detail

getData

public double[] getData()

setData

public void setData(double[] data)

getIndex

public int[] getIndex()

setIndex

public void setIndex(int[] index)

getUsed

public int getUsed()

setUsed

public void setUsed(int used)

getSize

public int getSize()

setSize

public void setSize(int size)

grow

public void grow(int newsize,
                 boolean bottom)

Grows or shrinks the vector to the given size

Parameters:

newsize - The new size of the vector

bottom - Boolean indicating wether the elements are added on the top or bottom

grow

public void grow(SparseVector v)

Grows a vector with another vector

Parameters:

v - The vector to be concatinated

bottom - Wether v is added before or after the vector

transpose

public Matrix transpose()

Transposes a vector

Specified by:

transpose in interface Matrix

Returns:

Returns a new transposed vector

clone

public SparseVector clone()

Creates a deep copy of the vector

Overrides:

clone in class java.lang.Object

Returns:

A deep copy of the vector

toString

public java.lang.String toString()

String representation of this sparse vector.

Overrides:

toString in class java.lang.Object

getIndex

public int getIndex(int ind)

Sets the index of a sparse vector inpired by http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ressim/mtj/src/no/uib/cipr/matrix/sparse/SparseVector.java?rev=HEAD&content-type=text/vnd.viewcvs-markup ;)

Parameters:

ind -

val -

Returns:

set

public void set(int in,
                double value)

Sets the entry of the vector to a given value

Parameters:

in - The entry of the vector to be altered

value - The new value

get

public double get(int index)

Gets the value at index inpired by http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ressim/mtj/src/no/uib/cipr/matrix/sparse/SparseVector.java?rev=HEAD&content-type=text/vnd.viewcvs-markup ;)

Parameters:

index -

Returns:

get

public double[] get()

Returns the vector as a double array

Returns:

The representation of the vector as array

dot

public double dot(SparseVector y)

Calculates the dot product (or scalar product, inner product) of two vectors

Parameters:

y - The second vector for the dot product

Returns:

The dot product of this and the vector y

plus

public SparseVector plus(Matrix y)

Adds a second vector to the vector

Specified by:

plus in interface Matrix

Parameters:

y - The second vector

Returns:

this+y

dotdumb

public double dotdumb(SparseVector y)

Calculates the dot product of this vector and the vector y

Parameters:

y - The second vector for the dot product

Returns:

The dot product of this and the second vector

dot

public double dot(double[] ydata)

Calculates the dot product of this vector and the vector y

Parameters:

ydata - The second vector implicitly given as double array

Returns:

The dot product of this and y

times

public SparseVector times(double c)

Multiplies the vector with a scalar

Parameters:

c - The scalar to be multiplied with the vector

Returns:

Returns the vector multiplied with the scalar

get

public double get(int row,
                  int column)

Gets the value of the vector at the position donated by row and column. Note: if the vector is not a linevector, column must be equal to zero, otherwise an exception will be thrown. If the vector is a linevector on the other hand, the row must be equal to zero likewise.

Specified by:

get in interface Matrix

Parameters:

row - The row of the entry

column - The column of the entry

Returns:

The value at the entry

getColNum

public int getColNum()

Returns the number of columns of the vector. Note: if this vector is not a linevector the value is, of course, always 1.

Specified by:

getColNum in interface Matrix

Returns:

The number of columns

getRowNum

public int getRowNum()

Returns the number of rows of the vector. Note: if this vector is a linevector the value is, of course, always 1.

Specified by:

getRowNum in interface Matrix

Returns:

The number of rows of the vector

times

public Matrix times(Matrix multiplier)

Multiplies the vector with a matrix

Specified by:

times in interface Matrix

Parameters:

multiplier - The matrix with which the vector should be multiplied

Returns:

this*multiplier

set

public void set(int row,
                int column,
                double value)

Sets a certain entry of the vector to the given value.

Specified by:

set in interface Matrix

add

public SparseVector add(SparseVector v)

Adds two sparse vectors

Parameters:

v - The vector to be added

Returns:

The sum of the two vectors

equals

public boolean equals(java.lang.Object o)

Compares two vectors. Notice: if the Object o isn't a probable SparseVector, it can't be compared yet.

Overrides:

equals in class java.lang.Object

Parameters:

v - The vector to be compared to

Returns:

True, if the second vector provides the same values, false otherwise. Note that the vectors don't need to be identical in the data-arrays, so it's okay when one vector explicitly safes a zero argument and the other doesn't.

equals

public boolean equals(SparseVector v)

Compares two SparseVectors

Parameters:

v - The vector to be compared to

Returns:

True, if the second vector provides the same values, false otherwise. Note that the vectors don't need to be identical in the data-arrays, so it's okay when one vector explicitly safes a zero argument and the other doesn't.

main

public static void main(java.lang.String[] args)

getNonZeroElementIterator

public NonZeroElementIterator getNonZeroElementIterator()

Specified by:

getNonZeroElementIterator in interface Matrix