org.jscience.chemistry.quantum.math.matrix
Class Matrix

java.lang.Object
  org.jscience.chemistry.quantum.math.matrix.Matrix

All Implemented Interfaces:

java.lang.Cloneable

public class Matrix
extends java.lang.Object
implements java.lang.Cloneable

A general NxM real matrix.

Field Summary

protected int	columnCount Holds value of property columnCount.
protected double[][]	matrix Holds value of property matrix.
protected int	rowCount Holds value of property rowCount.

Constructor Summary

Matrix(double[][] a)
Creates a new instance of Matrix, based on already allocated 2D array

Matrix(int n)
Creates a new instance of square (NxN) Matrix

Matrix(int n, int m)
Creates a new instance of NxM Matrix

Method Summary

Matrix	add(Matrix b) Simple matrix addition of two square matrices: this + b
java.lang.Object	clone() clone this vector ;) Cloning is getting interesting!
int	getColumnCount() Getter for property columnCount.
double[][]	getMatrix() Getter for property matrix.
double	getMatrixAt(int i, int j) Getter for property matrix.
int	getRowCount() Getter for property rowCount.
void	makeIdentity() make the current matrix an identity matrix, all diagonals as 1.0 and non-diagonals zero only sensible if a square matrix
Matrix	mul(Matrix b) Simple matrix multiplication of two matrices: this * b
double	rootMeanSquare() rootMeanSquare() - method to compute the root mean square of elements of a diagonal.
void	setColumnCount(int columnCount) Setter for property columnCount.
void	setMatrix(double[][] matrix) Setter for property matrix.
void	setMatrixAt(int i, int j, double value) Getter for property matrix.
void	setRowCount(int rowCount) Setter for property rowCount.
Matrix	similarityTransform(Matrix x) Similarity Transform : XAX' :: x * this * x'
Matrix	similarityTransformT(Matrix x) Similarity Transform : X'AX :: x' * this * x
double	sumOffDiagonal() Absolute sum of off-diagonal elements.
Matrix	symmetricOrthogonalization() Symmetric orthogonalization of the real symmetric matrix X (this).
java.lang.String	toString() overridden toString()
double	trace() Tr(this) = sum(diagonal(this)); Only valid if this a square matrix.
Matrix	transpose() Transpose a real matrix A (A')

Methods inherited from class java.lang.Object

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

Field Detail

matrix

protected double[][] matrix

Holds value of property matrix.

rowCount

protected int rowCount

Holds value of property rowCount.

columnCount

protected int columnCount

Holds value of property columnCount.

Constructor Detail

Matrix

public Matrix(int n,
              int m)

Creates a new instance of NxM Matrix

Parameters:

n - the first dimension

m - the second dimension

Matrix

public Matrix(int n)

Creates a new instance of square (NxN) Matrix

Parameters:

n - the dimension

Matrix

public Matrix(double[][] a)

Creates a new instance of Matrix, based on already allocated 2D array

Parameters:

a - the 2D array

Method Detail

add

public Matrix add(Matrix b)

Simple matrix addition of two square matrices: this + b

Parameters:

b - the matrix to which to add

Returns:

the result Cij = (Aij + Bij)

mul

public Matrix mul(Matrix b)

Simple matrix multiplication of two matrices: this * b

Parameters:

b - the matrix to which to multiply

Returns:

the result Cij = Sum(Aik*Bkj)

transpose

public Matrix transpose()

Transpose a real matrix A (A')

Returns:

the transposed instance

trace

public double trace()

Tr(this) = sum(diagonal(this)); Only valid if this a square matrix.

Returns:

the trace of this matrix

similarityTransform

public Matrix similarityTransform(Matrix x)

Similarity Transform : XAX' :: x * this * x'

Parameters:

x - the pre multiplier

Returns:

XAX'

similarityTransformT

public Matrix similarityTransformT(Matrix x)

Similarity Transform : X'AX :: x' * this * x

Parameters:

x - the post multiplier

Returns:

X'AX

symmetricOrthogonalization

public Matrix symmetricOrthogonalization()

Symmetric orthogonalization of the real symmetric matrix X (this). This is given by U'(1/sqrt(lambda))U, where lambda, U are the eigenvalues/vectors

Returns:

a matrix object U'(1/sqrt(lambda))U

makeIdentity

public void makeIdentity()

make the current matrix an identity matrix, all diagonals as 1.0 and non-diagonals zero
only sensible if a square matrix

rootMeanSquare

public double rootMeanSquare()

rootMeanSquare() - method to compute the root mean square of elements of a diagonal. This is one type of matrix norm. sqrt(sum(A_ii)).

sumOffDiagonal

public double sumOffDiagonal()

Absolute sum of off-diagonal elements.

Returns:

Sum(a[i][j],i!=j)

getMatrix

public double[][] getMatrix()

Getter for property matrix.

Returns:

Value of property matrix.

getMatrixAt

public double getMatrixAt(int i,
                          int j)

Getter for property matrix.

Parameters:

i - index i

j - index j

Returns:

Value of property matrix.

setMatrix

public void setMatrix(double[][] matrix)

Setter for property matrix.

Parameters:

matrix - New value of property matrix.

setMatrixAt

public void setMatrixAt(int i,
                        int j,
                        double value)

Getter for property matrix.

Parameters:

i - index i

j - index j

value - the new value

toString

public java.lang.String toString()

overridden toString()

Overrides:

toString in class java.lang.Object

clone

public java.lang.Object clone()

clone this vector ;) Cloning is getting interesting! :)

Overrides:

clone in class java.lang.Object

Returns:

the clone

getRowCount

public int getRowCount()

Getter for property rowCount.

Returns:

Value of property rowCount.

setRowCount

public void setRowCount(int rowCount)

Setter for property rowCount.

Parameters:

rowCount - New value of property rowCount.

getColumnCount

public int getColumnCount()

Getter for property columnCount.

Returns:

Value of property columnCount.

setColumnCount

public void setColumnCount(int columnCount)

Setter for property columnCount.

Parameters:

columnCount - New value of property columnCount.