org.encog.mathutil.matrices

Class MatrixMath

java.lang.Object

org.encog.mathutil.matrices.MatrixMath

public final class MatrixMath
extends java.lang.Object

This class can perform many different mathematical operations on matrixes. The matrixes passed in will not be modified, rather a new matrix, with the operation performed, will be returned.

Method Summary

Modifier and Type	Method and Description
static Matrix	add(Matrix a, Matrix b) Add two matrixes.
static void	copy(Matrix source, Matrix target) Copy from one matrix to another.
static Matrix	deleteCol(Matrix matrix, int deleted) Delete one column from the matrix.
static Matrix	deleteRow(Matrix matrix, int deleted) Delete a row from the matrix.
static double	determinant(Matrix m)
static Matrix	divide(Matrix a, double b) Return a matrix with each cell divided by the specified value.
static double	dotProduct(Matrix a, Matrix b) Compute the dot product for the two matrixes.
static Matrix	identity(int size) Return an identity matrix of the specified size.
static Matrix	multiply(Matrix a, double b) Return the result of multiplying every cell in the matrix by the specified value.
static double[]	multiply(Matrix a, double[] d)
static Matrix	multiply(Matrix a, Matrix b) Return the product of the first and second matrix.
static Matrix	subtract(Matrix a, Matrix b) Return the results of subtracting one matrix from another.
static Matrix	transpose(Matrix input) Return the transposition of a matrix.
static double	vectorLength(Matrix input) Calculate the length of a vector.

Methods inherited from class java.lang.Object

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

Method Detail

add

public static Matrix add(Matrix a,
                         Matrix b)

Add two matrixes.

Parameters:

a - The first matrix to add.

b - The second matrix to add.

Returns:

A new matrix of the two added.

copy

public static void copy(Matrix source,
                        Matrix target)

Copy from one matrix to another.

Parameters:

source - The source matrix for the copy.

target - The target matrix for the copy.

deleteCol

public static Matrix deleteCol(Matrix matrix,
                               int deleted)

Delete one column from the matrix. Does not actually touch the source matrix, rather a new matrix with the column deleted is returned.

Parameters:

matrix - The matrix.

deleted - The column to delete.

Returns:

A matrix with the column deleted.

deleteRow

public static Matrix deleteRow(Matrix matrix,
                               int deleted)

Delete a row from the matrix. Does not actually touch the matrix, rather returns a new matrix.

Parameters:

matrix - The matrix.

deleted - Which row to delete.

Returns:

A new matrix with the specified row deleted.

divide

public static Matrix divide(Matrix a,
                            double b)

Return a matrix with each cell divided by the specified value.

Parameters:

a - The matrix to divide.

b - The value to divide by.

Returns:

A new matrix with the division performed.

dotProduct

public static double dotProduct(Matrix a,
                                Matrix b)

Compute the dot product for the two matrixes. To compute the dot product, both

Parameters:

a - The first matrix.

b - The second matrix.

Returns:

The dot product.

identity

public static Matrix identity(int size)

Return an identity matrix of the specified size.

Parameters:

size - The number of rows and columns to create. An identity matrix is always square.

Returns:

An identity matrix.

multiply

public static Matrix multiply(Matrix a,
                              double b)

Return the result of multiplying every cell in the matrix by the specified value.

Parameters:

a - The first matrix.

b - The second matrix.

Returns:

The result of the multiplication.

multiply

public static Matrix multiply(Matrix a,
                              Matrix b)

Return the product of the first and second matrix.

Parameters:

a - The first matrix.

b - The second matrix.

Returns:

The result of the multiplication.

subtract

public static Matrix subtract(Matrix a,
                              Matrix b)

Return the results of subtracting one matrix from another.

Parameters:

a - The first matrix.

b - The second matrix.

Returns:

The results of the subtraction.

transpose

public static Matrix transpose(Matrix input)

Return the transposition of a matrix.

Parameters:

input - The matrix to transpose.

Returns:

The matrix transposed.

vectorLength

public static double vectorLength(Matrix input)

Calculate the length of a vector.

Parameters:

input - The matrix to calculate the length of.

Returns:

Vector length.

determinant

public static double determinant(Matrix m)

multiply

public static double[] multiply(Matrix a,
                                double[] d)