edu.nps.moves.deadreckoning.utils
Class Matrix

java.lang.Object
  edu.nps.moves.deadreckoning.utils.Matrix

public class Matrix
extends java.lang.Object

A class that performs some basic Matrix manipulations, stopping short of Eigenvectors, Single Value Decomposition, LU, and other more advaced manipulations.

1. Multiplication
2. Inverse
3. Add
4. Subtract
5. Transpose
6. Row swap
7. Sub determinate (2x2)

Author:

Sheldon L. Snyder

Constructor Summary

Matrix(int dimension)
create a square matrix initialized to the identity

Matrix(int rows, int cols)
create a matrix of any dimensions initialized to all zeroes.

Matrix(Matrix M)
Creates a matrix of a matrix...a copy

Method Summary

Matrix	add(Matrix M2) Adds two matrices together
static void	add(Matrix r1, double a) Adds a constant to each element of this matrix
static Matrix	add(Matrix M1, Matrix M2) Static method to add any two matrices
double	cell(int i, int j) return the value in this matrix located at the ith row and jth column
int	cols() Get the number of columns in this matrix
static double	det(double d1, double d2, double d3, double d4) Solves the determinate of this 2x2 matrix
static Matrix	inversMat3x3(Matrix in) Given a 3 x 3 matrix and using Determinats to solve for inverse
Matrix	mult(double a) scales a matrix, but does not destroy the content of the original
Matrix	mult(Matrix M2) Multiplies 2 matrixes together
static Matrix	mult(Matrix M1, Matrix M2) multiplies two matrixes together None Destructive
void	multSelf(double a) Scalar multiply in place
static double[]	multVec(Matrix A, double[] x) Performs Ax multiplication
void	print() Prints the content of a matrix to standard out
void	replace(Matrix M) copy each cell from M to this.data
int	rows() Gets the number of rows in this matrix
void	setCell(int i, int j, double value) set the value of the cell at the ith row and jth column to value
Matrix	subtract(Matrix M2) Subtracts a matrix from this
static Matrix	subtract(Matrix M1, Matrix M2) static Subtraces M2 from M1 5 = 8 - 3
static Matrix	transpose(Matrix in) Makes a transpose of the input matrix

Methods inherited from class java.lang.Object

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

Constructor Detail

Matrix

public Matrix(int dimension)

create a square matrix initialized to the identity

Parameters:

dimension - - size to make a square matrix

Matrix

public Matrix(int rows,
              int cols)

create a matrix of any dimensions initialized to all zeroes.

Parameters:

rows -

cols -

Matrix

public Matrix(Matrix M)
       throws MatrixException

Creates a matrix of a matrix...a copy

Parameters:

M - - matrix to copy

Throws:

MatrixException

Method Detail

replace

public void replace(Matrix M)
             throws MatrixException

copy each cell from M to this.data

Replaces the value of this...destructive copy

to just get a copy of a matrix
Matrix mm33 is a matrix initialized to some value
Matrix inv = Matrix.inverseMxM(mm33);

This makes a copy of mm33 into inv. mm33 is not altered in this process.

Parameters:

M - - matrix to copy

Throws:

MatrixException

cols

public int cols()

Get the number of columns in this matrix

Returns:

the number of columns in this matrix

rows

public int rows()

Gets the number of rows in this matrix

Returns:

the number rows in this matrix

cell

public double cell(int i,
                   int j)
            throws MatrixException

return the value in this matrix located at the ith row and jth column

Should have made this getCell, but I got too far along to make all the changes....

Parameters:

i - - row

j - - column

Returns:

- the value at row i and column j

Throws:

MatrixException

setCell

public void setCell(int i,
                    int j,
                    double value)
             throws MatrixException

set the value of the cell at the ith row and jth column to value

Parameters:

i - - row

j - - column

value - - the double to put in the cell (i,j)

Throws:

MatrixException

add

public Matrix add(Matrix M2)
           throws MatrixException

Adds two matrices together

non-destructive

Parameters:

M2 - - what to add to this

Returns:

this matrix with M2 added to itthis + M2 of same only if both are same dim

Throws:

MatrixException

add

public static void add(Matrix r1,
                       double a)
                throws java.lang.Exception

Adds a constant to each element of this matrix

Parameters:

r1 - - the matrix to receve the addition

a - - the vlaue to ad to each cell of the matrix

Throws:

java.lang.Exception

add

public static Matrix add(Matrix M1,
                         Matrix M2)
                  throws MatrixException

Static method to add any two matrices

Parameters:

M1 -

M2 -

Returns:

adds m1 and m2 only if of the same size

Throws:

MatrixException

subtract

public Matrix subtract(Matrix M2)
                throws MatrixException

Subtracts a matrix from this

non-destructive

Parameters:

M2 -

Returns:

this - M2

Throws:

MatrixException

subtract

public static Matrix subtract(Matrix M1,
                              Matrix M2)
                       throws MatrixException

static Subtraces M2 from M1 5 = 8 - 3

Parameters:

M1 - - subtraced from matrix (the 8 in the above)

M2 - - what is subtracte (the 3 in the above)

Returns:

- the result of subrtaction (the 5 in the above)

Throws:

MatrixException

mult

public Matrix mult(double a)
            throws MatrixException

scales a matrix, but does not destroy the content of the original

Non-destructive multiply

Parameters:

a - - the scalar

Returns:

this multipled by a

Throws:

MatrixException

transpose

public static Matrix transpose(Matrix in)
                        throws MatrixException

Makes a transpose of the input matrix

rows become columns
Row 1 is now column 1
Row 2 is now column 2
Row n is now column n


Parameters:

in - - input matrix

Returns:

- the transpose of the input

Throws:

MatrixException

multVec

public static double[] multVec(Matrix A,
                               double[] x)
                        throws MatrixException

Performs Ax multiplication

Parameters:

A -

x -

Returns:

the resulting array

Throws:

MatrixException

multSelf

public void multSelf(double a)

Scalar multiply in place

Destructive multiply

Parameters:

a -

mult

public Matrix mult(Matrix M2)
            throws MatrixException

Multiplies 2 matrixes together

3x1 * 1x3 = 3x3

None Destructive

Parameters:

M2 -

Returns:

a Matrix of this * M2

Throws:

MatrixException

mult

public static Matrix mult(Matrix M1,
                          Matrix M2)
                   throws MatrixException

multiplies two matrixes together None Destructive

Parameters:

M1 - left hand side

M2 - right hand side

Returns:

a Matrix of M1 * M2

Throws:

MatrixException

print

public void print()
           throws MatrixException

Prints the content of a matrix to standard out

Throws:

MatrixException

inversMat3x3

public static Matrix inversMat3x3(Matrix in)
                           throws MatrixException

Given a 3 x 3 matrix and using Determinats to solve for inverse

Parameters:

in - - input 3x3 matrix

Returns:

- the inverse of this matrix

Throws:

MatrixException

det

public static double det(double d1,
                         double d2,
                         double d3,
                         double d4)

Solves the determinate of this 2x2 matrix

Parameters:

d1 - - a11

d2 - - a12

d3 - - a21

d4 - - a22

Returns:

the determinate of this 2x2