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

```
public class Matrix
extends Object
```
This class contains a matrix.

Author:

Stephan Michels <stephan@vern.chem.tu-berlin.de>

Source code:
main

Belongs to CDK module:
qm

Created on:

2001-06-07

Field Summary

Fields
Modifier and Type Field Description

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

Constructors
Constructor Description

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

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

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Matrix`	`add(Matrix b)`	Adds two matrices.
`double`	`contraction()`
`Matrix`	`diagonalize(int maxNumRot)`	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
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - matrix
```
public final double[][] matrix
```
    the content of this matrix
  - rows
```
public final 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 maxNumRot)
```
    Diagonalize this matrix with the Jacobi algorithm.
    
    Parameters:
    
    maxNumRot - 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.

Modifier and Type	Field	Description
`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	Description
`Matrix(double[][] array)`	Creates a Matrix with content of an array.
`Matrix(int rows, int columns)`	Creates a new Matrix.

Class Matrix

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

matrix

rows

columns

Constructor Detail

Matrix

Matrix

Method Detail

getRows

getColumns

getVectorFromRow

getVectorFromColumn

getVectorFromDiagonal

add

sub

mul

mul

mul

duplicate

transpose

similar

contraction

toString

diagonalize

elimination

orthonormalize

normalize