org.faceless.graph.math
Class Matrix

java.lang.Object
  org.faceless.graph.math.Matrix

public class Matrix
extends Object

A simple class defining a mathematical matrix.

Matrix

public Matrix(int cols,
              int rows)

Create a new Matrix of the specified number of rows and columns

Matrix

public Matrix(Matrix m)

Create a new Matrix that's a clone of the specified matrix

set

public void set(int col,
                int row,
                double val)

Set the element at the specified row and column to the specified value

Parameters:

col - the column to set the value in, from 0 to getCols()-1

row - the row to set the value in, from 0 to getRows()-1

val - the value to set.

Throws:

ArrayIndexOutOfBoundsException - if the matrix doesn't contain the specified row or column

get

public double get(int col,
                  int row)

Get the element at the specified row and column.

Parameters:

col - the column to set the value in, from 0 to getCols()-1

row - the row to set the value in, from 0 to getRows()-1

Throws:

ArrayIndexOutOfBoundsException - if the matrix doesn't contain the specified row or column

toString

public String toString()

Overrides:

toString in class Object

exchangeRows

public Matrix exchangeRows(int row1,
                           int row2)

Return a duplicate of the current matrix with the specified rows swapped

identity

public static Matrix identity(int ord)

Return a new Identity Matrix of the specified size

Parameters:

ord - the number of rows and columns in the matrix

add

public Matrix add(Matrix m)

Return a new matrix that is the sum of this matrix and the specified matrix. The current matrix is unmodified

getRows

public int getRows()

Return the number of rows in this matrix

getCols

public int getCols()

Return the number of columns in this matrix

mul

public Matrix mul(double fac)

Return a new matrix that is the product of this matrix and the specified factor. The current matrix is unmodified

mul

public Matrix mul(Matrix m)

Return a new matrix that is the product of this matrix and the specified matrix. The current matrix is unmodified

Throws:

IllegalArgumentException - if the two matrices are incompatible sizes.

div

public Matrix div(Matrix m)

Return a new matrix that is the result of this matrix divided by the specified matrix. This is the same as multiplying by the inverse of the specified matrix. The current matrix is unmodified.

Throws:

IllegalArgumentException - if the two matrices are incompatible sizes.

ArithmeticException - if the second matrix has no inverse.

appendHorizontal

public Matrix appendHorizontal(Matrix m)

Append the specified matrix to the current matrix by extending the number of columns in the current matrix

appendVertical

public Matrix appendVertical(Matrix m)

Append the specified matrix to the current matrix by extending the number of columns in the current matrix

subMatrix

public Matrix subMatrix(int col,
                        int row,
                        int numcols,
                        int numrows)

Return a subset of this matrix consisiting of just the specified columns and rows

inverse

public Matrix inverse()
               throws ArithmeticException

Return the inverse of the current matrix

Throws:

ArithmeticException - if there is no inverse

pivot

public Matrix pivot(int col,
                    int row)

Pivot the current matrix around the specified row and column

main

public static void main(String[] args)