org.openscience.cdk.math
Class Matrix

java.lang.Object
  org.openscience.cdk.math.Matrix

public class Matrix
extends Object

This class contains a matrix.

Author:

Stephan Michels

Created on:

2001-06-07

Belongs to CDK module:

qm

Source code:

HEAD

Field Summary

int	columns the number of columns of this matrix
double[][]	matrix the content of this matrix
int	rows the number of rows of this matrix

Constructor Summary

Matrix(double[][] array)
Creates a Matrix with content of an array.

Matrix(int rows, int columns)
Creates a new Matrix.

Method Summary

Matrix	add(Matrix b) Adds two matrices.
double	contraction()
Matrix	diagonalize(int nrot) Diagonalize this matrix with the Jacobi algorithm.
Matrix	duplicate() Copies a matrix.
static Vector	elimination(Matrix matrix, Vector vector) Solves a linear equation system with Gauss elimination.
int	getColumns() Returns the number of columns.
int	getRows() Returns the number of rows.
Vector	getVectorFromColumn(int index) Creates a Vector with the content of a column from this Matrix.
Vector	getVectorFromDiagonal() Creates a Vector with the content of the diagonal elements from this Matrix.
Vector	getVectorFromRow(int index) Creates a Vector with the content of a row from this Matrix.
Matrix	mul(double a) Multiplies a scalar with this Matrix.
Matrix	mul(Matrix b) Multiplies this Matrix with another one.
Vector	mul(Vector a) Multiplies a Vector with this Matrix.
Matrix	normalize(Matrix S) Normalizes the vectors of this matrix.
Matrix	orthonormalize(Matrix S) Orthonormalize the vectors of this matrix by Gram-Schmidt.
Matrix	similar(Matrix U) Similar transformation Ut * M * U
Matrix	sub(Matrix b) Subtracts from two matrices.
String	toString() Return a matrix as a String.
Matrix	transpose() Transposes a matrix.

Methods inherited from class java.lang.Object

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

Field Detail

matrix

public double[][] matrix

the content of this matrix

rows

public int rows

the number of rows of this matrix

columns

public int columns

the number of columns of this matrix

Constructor Detail

Matrix

public Matrix(int rows,
              int columns)

Creates a new Matrix.

Matrix

public Matrix(double[][] array)

Creates a Matrix with content of an array.

Method Detail

getRows

public int getRows()

Returns the number of rows.

getColumns

public int getColumns()

Returns the number of columns.

getVectorFromRow

public Vector getVectorFromRow(int index)

Creates a Vector with the content of a row from this Matrix.

getVectorFromColumn

public Vector getVectorFromColumn(int index)

Creates a Vector with the content of a column from this Matrix.

getVectorFromDiagonal

public Vector getVectorFromDiagonal()

Creates a Vector with the content of the diagonal elements from this Matrix.

add

public Matrix add(Matrix b)

Adds two matrices.

sub

public Matrix sub(Matrix b)

Subtracts from two matrices.

mul

public Matrix mul(Matrix b)

Multiplies this Matrix with another one.

mul

public Vector mul(Vector a)

Multiplies a Vector with this Matrix.

mul

public Matrix mul(double a)

Multiplies a scalar with this Matrix.

duplicate

public Matrix duplicate()

Copies a matrix.

transpose

public Matrix transpose()

Transposes a matrix.

similar

public Matrix similar(Matrix U)

Similar transformation Ut * M * U

contraction

public double contraction()

toString

public String toString()

Return a matrix as a String.

Overrides:

toString in class Object

diagonalize

public Matrix diagonalize(int nrot)

Diagonalize this matrix with the Jacobi algorithm.

Parameters:

nrot - Count of max. rotations

Returns:

Matrix m, with m^t * this * m = diagonal

Keywords:

Jacobi algorithm, diagonalization

elimination

public static Vector elimination(Matrix matrix,
                                 Vector vector)

Solves a linear equation system with Gauss elimination.

Keywords:

Gauss elimination

orthonormalize

public Matrix orthonormalize(Matrix S)

Orthonormalize the vectors of this matrix by Gram-Schmidt.

Keywords:

orthonormalization, Gram-Schmidt algorithm

normalize

public Matrix normalize(Matrix S)

Normalizes the vectors of this matrix.