SciLib.Math
Class matrix

java.lang.Object
  SciLib.Math.matrix

public class matrix
extends java.lang.Object

This class contains some methods to handle the matrix problems

Constructor Summary

matrix()
Allocates a 0x0 matrix.

matrix(double[][] ma)
Make a matrix from a two-dimensional array.

matrix(int rows, int columns)
Allocates a m x n matrix.

matrix(matrix ma)
Make a copy of a matrix ma.

Method Summary

double	elementAt(int i, int j) return the value element of matrix at row i and column j.
vector	getColumn(int j) return a vector that contains all elements of the jth column.
int	getColumns() return the number of columns.
double[][]	getData() return a two-dimensional array that contains all elements of matrix.
vector	getRow(int i) return a vector that contains all elements of the ith row.
int	getRows() return the number of rows.
static matrix	identity(int n) Make the n x n identity mattrix
double	max() Return the maximum value of the matrix
double	min() Return the minimum value of the matrix
void	minus(matrix x) minus this matrix with the matrix x and store the result in this matrix
static matrix	minus(matrix x, matrix y) minus two matrices x, y.
static matrix	mult(matrix x, matrix y) Make a matrix A = x*y
static vector	mult(matrix A, vector x) compute Ax
void	plus(matrix x) plus this matrix with the matrix x and store the result in this matrix
static matrix	plus(matrix x, matrix y) plus two matrices x, y.
void	print() Print all elements of the matrix using System.out.
void	random(double a, double b) Fill this matrix with random values between a and b.
void	read(java.lang.String fileName) Read data from a file to a matrix.
void	resize(int rows, int columns) Change the size of the matrix.
void	scale(double s) Scaling all elements of the matrix with a factor s.
void	scaling(double a, double b) scaling
matrix	scaling(matrix m, double a, double b) scaling
void	setColumn(int i, vector v) set column(i) = v
void	setElementAt(double x, int i, int j) Change the value element of matrix at row i and column j.
void	setRow(int i, vector v) set row(i) = v
matrix	transpose() Make the transpose matrix of this matrix
static matrix	transpose(matrix ma) Make the transpose matrix of a matrix ma
void	write(java.lang.String fileName) Write all elements of the matrix to a file.
void	write(java.lang.String fileName, int n) Write all elements of the matrix to a file with the n deimal digits format.

Methods inherited from class java.lang.Object

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

Constructor Detail

matrix

public matrix()

Allocates a 0x0 matrix.

matrix

public matrix(int rows,
              int columns)

Allocates a m x n matrix.

Parameters:

rows - The number of rows

columns - The number of columns

matrix

public matrix(double[][] ma)

Make a matrix from a two-dimensional array.

Parameters:

ma - A two-dimensional array

matrix

public matrix(matrix ma)

Make a copy of a matrix ma.

Parameters:

ma - A matrix

Method Detail

elementAt

public double elementAt(int i,
                        int j)
                 throws java.lang.ArrayIndexOutOfBoundsException

return the value element of matrix at row i and column j.

Parameters:

i - An integer

j - An integer

Returns:

A double value

Throws:

java.lang.ArrayIndexOutOfBoundsException

setElementAt

public void setElementAt(double x,
                         int i,
                         int j)
                  throws java.lang.ArrayIndexOutOfBoundsException

Change the value element of matrix at row i and column j.

Parameters:

i - An integer

j - An integer

x - A double value

Throws:

java.lang.ArrayIndexOutOfBoundsException

getRows

public final int getRows()

return the number of rows.

Returns:

An integer

getColumns

public final int getColumns()

return the number of columns.

Returns:

An integer

getData

public double[][] getData()

return a two-dimensional array that contains all elements of matrix.

Returns:

A two-dimensional array

resize

public void resize(int rows,
                   int columns)

Change the size of the matrix.

Parameters:

rows - The new numbers of rows

columns - The new numbers of columns

getRow

public vector getRow(int i)

return a vector that contains all elements of the ith row.

Returns:

A vector

getColumn

public vector getColumn(int j)

return a vector that contains all elements of the jth column.

Returns:

A vector

min

public final double min()

Return the minimum value of the matrix

Returns:

A double value

max

public final double max()

Return the maximum value of the matrix

Returns:

A double value

scale

public void scale(double s)

Scaling all elements of the matrix with a factor s.

Parameters:

s - A double value that is the sacling factor

random

public void random(double a,
                   double b)

Fill this matrix with random values between a and b.

Parameters:

a - A double value

b - A double value

plus

public void plus(matrix x)
          throws SizeException

plus this matrix with the matrix x and store the result in this matrix

Parameters:

x - A vector

Throws:

SizeException

plus

public static matrix plus(matrix x,
                          matrix y)
                   throws SizeException

plus two matrices x, y. The result is stored in a new matrix

Parameters:

x - A matrix

y - A matrix

Returns:

A matrix that is equal to x + y

Throws:

SizeException

minus

public void minus(matrix x)
           throws SizeException

minus this matrix with the matrix x and store the result in this matrix

Parameters:

x - A vector

Throws:

SizeException

minus

public static matrix minus(matrix x,
                           matrix y)
                    throws SizeException

minus two matrices x, y. The result is stored in a new matrix

Parameters:

x - A matrix

y - A matrix

Returns:

A matrix that is equal to x - y

Throws:

SizeException

mult

public static matrix mult(matrix x,
                          matrix y)
                   throws SizeException

Make a matrix A = x*y

Parameters:

x - A matrix

y - A matrix

Returns:

A matrix that is equal to x*y

Throws:

SizeException

mult

public static vector mult(matrix A,
                          vector x)

compute Ax

Parameters:

A - A matrix

x - A vector

Returns:

A vector

identity

public static matrix identity(int n)

Make the n x n identity mattrix

Parameters:

n - An integer

Returns:

The n x n identity mattrix

transpose

public static matrix transpose(matrix ma)

Make the transpose matrix of a matrix ma

Parameters:

ma - A matrix

Returns:

A mattrix

transpose

public matrix transpose()

Make the transpose matrix of this matrix

Returns:

A mattrix

write

public void write(java.lang.String fileName)

Write all elements of the matrix to a file.

Parameters:

fileName - A String

write

public void write(java.lang.String fileName,
                  int n)

Write all elements of the matrix to a file with the n deimal digits format.

Parameters:

fileName - A String

read

public void read(java.lang.String fileName)

Read data from a file to a matrix.

Parameters:

fileName - a String

print

public final void print()

Print all elements of the matrix using System.out.

setRow

public void setRow(int i,
                   vector v)

set row(i) = v

Parameters:

i - An integer value, the row index

v - A vector

setColumn

public void setColumn(int i,
                      vector v)

set column(i) = v

Parameters:

i - An integer value, the column index

v - A vector

scaling

public matrix scaling(matrix m,
                      double a,
                      double b)

scaling

Parameters:

m - A matrix that will be scaled

a - A double, the lower bound of all elements in the matrix

b - A double, the upper bound of all elements in the matrix

Returns:

A matrix

scaling

public void scaling(double a,
                    double b)

scaling

Parameters:

a - A double, the lower bound of all elements in the matrix

b - A double, the upper bound of all elements in the matrix