Package jexer.bits

Class MathUtils

java.lang.Object

jexer.bits.MathUtils

public class MathUtils
extends java.lang.Object

MathUtils contains miscellaneous mathemathical computations.

The eigenvector functions are ultimately based on the public-domain JAMA code. These specific ones were made available by Connelly Barnes at: http://barnesc.blogspot.com/2007/02/eigenvectors-of-3x3-symmetric-matrix.html

Method Summary

Modifier and Type	Method	Description
static void	eigen3(double[][] A, double[][] V, double[] d)	Compute the eigenvalues and eigenvectors of a symmetric 3x3 matrix.
static void	main(java.lang.String[] args)	Test the eigenvector code.

Methods inherited from class java.lang.Object

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

Method Detail

eigen3

public static void eigen3(double[][] A,
                          double[][] V,
                          double[] d)

Compute the eigenvalues and eigenvectors of a symmetric 3x3 matrix. Coordinates for the matrices are as A[row][col] and V[row][col].

Parameters:

A - input: the 3x3 matrix. It must be symmetric.

V - output: the eigenvectors. Each column is a vector. The first column (V[0][0], V[1][0], V[2][0]) will correspond to the first eigenvector (d[0]), the second column (V[0][1], V[1][1], V[2][1]) will correspond to the second eigenvector (d[1]), and the third column (V[0][2], V[1][2], V[2][2]) will correspond to the third eigenvector (d[2]).

d - output: the eigenvalues. These will be sorted smallest to largest.

main

public static void main(java.lang.String[] args)

Test the eigenvector code.

Parameters:

args - command line arguments