Package io.odilon.rs

Class Matrix

java.lang.Object

io.odilon.rs.Matrix

public class Matrix
extends Object

A matrix over the 8-bit Galois field. This class is not performance-critical, so the implementations are simple and straightforward.

Constructor Summary

Constructors

Constructor	Description
Matrix(byte[][] initData)	Initializes a matrix with the given row-major data.
Matrix(int initRows, int initColumns)	Initialize a matrix of zeros.

Method Summary

Modifier and Type	Method	Description
Matrix	augment(Matrix right)	Returns the concatenation of this matrix and the matrix on the right.
boolean	equals(Object other)	Returns true iff this matrix is identical to the other.
byte	get(int r, int c)	Returns the value at row r, column c.
int	getColumns()	Returns the number of columns in this matrix.
byte[]	getRow(int row)	Returns one row of the matrix as a byte array.
int	getRows()	Returns the number of rows in this matrix.
static Matrix	identity(int size)	Returns an identity matrix of the given size.
Matrix	invert()	Returns the inverse of this matrix.
void	set(int r, int c, byte value)	Sets the value at row r, column c.
Matrix	submatrix(int rmin, int cmin, int rmax, int cmax)	Returns a part of this matrix.
void	swapRows(int r1, int r2)	Exchanges two rows in the matrix.
Matrix	times(Matrix right)	Multiplies this matrix (the one on the left) by another matrix (the one on the right).
String	toBigString()	Returns a human-readable string of the matrix contents.
String	toString()	Returns a human-readable string of the matrix contents.

Methods inherited from class java.lang.Object

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

Constructor Detail

Matrix

public Matrix(int initRows,
              int initColumns)

Initialize a matrix of zeros.

Parameters:

initRows - The number of rows in the matrix.

initColumns - The number of columns in the matrix.

Matrix

public Matrix(byte[][] initData)

Initializes a matrix with the given row-major data.

Method Detail

identity

public static Matrix identity(int size)

Returns an identity matrix of the given size.

toString

public String toString()

Returns a human-readable string of the matrix contents. Example: [[1, 2], [3, 4]]

Overrides:

toString in class Object

toBigString

public String toBigString()

Returns a human-readable string of the matrix contents. Example: 00 01 02 03 04 05 06 07 08 09 0a 0b

getColumns

public int getColumns()

Returns the number of columns in this matrix.

getRows

public int getRows()

Returns the number of rows in this matrix.

get

public byte get(int r,
                int c)

Returns the value at row r, column c.

set

public void set(int r,
                int c,
                byte value)

Sets the value at row r, column c.

equals

public boolean equals(Object other)

Returns true iff this matrix is identical to the other.

Overrides:

equals in class Object

times

public Matrix times(Matrix right)

Multiplies this matrix (the one on the left) by another matrix (the one on the right).

augment

public Matrix augment(Matrix right)

Returns the concatenation of this matrix and the matrix on the right.

submatrix

public Matrix submatrix(int rmin,
                        int cmin,
                        int rmax,
                        int cmax)

Returns a part of this matrix.

getRow

public byte[] getRow(int row)

Returns one row of the matrix as a byte array.

swapRows

public void swapRows(int r1,
                     int r2)

Exchanges two rows in the matrix.

invert

public Matrix invert()

Returns the inverse of this matrix.

Throws:

IllegalArgumentException - when the matrix is singular and doesn't have an inverse.