Package org.hortonmachine.gears.utils.math.matrixes

Class Matrix

java.lang.Object

org.hortonmachine.gears.utils.math.matrixes.Matrix

Direct Known Subclasses:

ColumnVector, RowVector, SquareMatrix

public class Matrix
extends Object

From: Java Number Cruncher The Java Programmer's Guide to Numerical Computation by Ronald Mak The matrix class.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	nCols	number of columns
protected int	nRows	number of rows
protected double[][]	values	2-d array of values

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Matrix()	Default constructor.
	Matrix(double[][] values)	Constructor.
	Matrix(int rowCount, int colCount)	Constructor.

Method Summary

Modifier and Type	Method	Description
Matrix	add(Matrix m)	Add another matrix to this matrix.
double	at(int r, int c)	Get the value of element [r,c] in the matrix.
int	columnCount()	Get the column count.
double[][]	copyValues2D()	Copy the values of this matrix.
ColumnVector	getColumn(int c)	Get a column of this matrix.
RowVector	getRow(int r)	Get a row of this matrix.
Matrix	multiply(double k)	Multiply this matrix by a constant.
ColumnVector	multiply(ColumnVector cv)	Multiply this matrix by a column vector: this*cv
Matrix	multiply(Matrix m)	Multiply this matrix by another matrix.
RowVector	multiply(RowVector rv)	Multiply a row vector by this matrix: rv*this
int	rowCount()	Get the row count.
protected void	set(double[][] values)	Set this matrix from a 2-d array of values.
void	set(int r, int c, double value)	Set the value of element [r,c].
void	setColumn(ColumnVector cv, int c)	Set a column of this matrix from a column vector.
void	setRow(RowVector rv, int r)	Set a row of this matrix from a row vector.
Matrix	subtract(Matrix m)	Subtract another matrix from this matrix.
Matrix	transpose()	Return the transpose of this matrix.
double[][]	values()	Copy the values of this matrix.

Methods inherited from class java.lang.Object

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

Field Detail

nRows

protected int nRows

number of rows

nCols

protected int nCols

number of columns

values

protected double[][] values

2-d array of values

Constructor Detail

Matrix

protected Matrix()

Default constructor.

Matrix

public Matrix(int rowCount,
              int colCount)

Constructor.

Parameters:

rowCount - the number of rows

colCount - the number of columns

Matrix

public Matrix(double[][] values)

Constructor.

Parameters:

values - the 2-d array of values

Method Detail

rowCount

public int rowCount()

Get the row count.

Returns:

the row count

columnCount

public int columnCount()

Get the column count.

Returns:

the column count

at

public double at(int r,
                 int c)
          throws MatrixException

Get the value of element [r,c] in the matrix.

Parameters:

r - the row index

c - the column index

Returns:

the value

Throws:

numbercruncher.MatrixException - for an invalid index

MatrixException

getRow

public RowVector getRow(int r)
                 throws MatrixException

Get a row of this matrix.

Parameters:

r - the row index

Returns:

the row as a row vector

Throws:

numbercruncher.MatrixException - for an invalid index

MatrixException

getColumn

public ColumnVector getColumn(int c)
                       throws MatrixException

Get a column of this matrix.

Parameters:

c - the column index

Returns:

the column as a column vector

Throws:

numbercruncher.MatrixException - for an invalid index

MatrixException

values

public double[][] values()

Copy the values of this matrix.

Returns:

the values

copyValues2D

public double[][] copyValues2D()

Copy the values of this matrix.

Returns:

the copied values

set

public void set(int r,
                int c,
                double value)
         throws MatrixException

Set the value of element [r,c].

Parameters:

r - the row index

c - the column index

value - the value

Throws:

numbercruncher.MatrixException - for an invalid index

MatrixException

set

protected void set(double[][] values)

Set this matrix from a 2-d array of values. If the rows do not have the same length, then the matrix column count is the length of the shortest row.

Parameters:

values - the 2-d array of values

setRow

public void setRow(RowVector rv,
                   int r)
            throws MatrixException

Set a row of this matrix from a row vector.

Parameters:

rv - the row vector

r - the row index

Throws:

numbercruncher.MatrixException - for an invalid index or an invalid vector size

MatrixException

setColumn

public void setColumn(ColumnVector cv,
                      int c)
               throws MatrixException

Set a column of this matrix from a column vector.

Parameters:

cv - the column vector

c - the column index

Throws:

numbercruncher.MatrixException - for an invalid index or an invalid vector size

MatrixException

transpose

public Matrix transpose()

Return the transpose of this matrix.

Returns:

the transposed matrix

add

public Matrix add(Matrix m)
           throws MatrixException

Add another matrix to this matrix.

Parameters:

m - the matrix addend

Returns:

the sum matrix

Throws:

numbercruncher.MatrixException - for invalid size

MatrixException

subtract

public Matrix subtract(Matrix m)
                throws MatrixException

Subtract another matrix from this matrix.

Parameters:

m - the matrix subrrahend

Returns:

the difference matrix

Throws:

numbercruncher.MatrixException - for invalid size

MatrixException

multiply

public Matrix multiply(double k)

Multiply this matrix by a constant.

Parameters:

k - the constant

Returns:

the product matrix

multiply

public Matrix multiply(Matrix m)
                throws MatrixException

Multiply this matrix by another matrix.

Parameters:

m - the matrix multiplier

Returns:

the product matrix

Throws:

numbercruncher.MatrixException - for invalid size

MatrixException

multiply

public ColumnVector multiply(ColumnVector cv)
                      throws MatrixException

Multiply this matrix by a column vector: this*cv

Parameters:

cv - the column vector

Returns:

the product column vector

Throws:

numbercruncher.MatrixException - for invalid size

MatrixException

multiply

public RowVector multiply(RowVector rv)
                   throws MatrixException

Multiply a row vector by this matrix: rv*this

Parameters:

rv - the row vector

Returns:

the product row vector

Throws:

numbercruncher.MatrixException - for invalid size

MatrixException