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Jama.EigenvalueDecomposition Class Reference
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Public Member Functions

 EigenvalueDecomposition (Matrix Arg)
 
Matrix getV ()
 
double[] getRealEigenvalues ()
 
double[] getImagEigenvalues ()
 
Matrix getD ()
 

Detailed Description

Eigenvalues and eigenvectors of a real matrix.

If A is symmetric, then A = V*D*V' where the eigenvalue matrix D is diagonal and the eigenvector matrix V is orthogonal. I.e. A = V.times(D.times(V.transpose())) and V.times(V.transpose()) equals the identity matrix.

If A is not symmetric, then the eigenvalue matrix D is block diagonal with the real eigenvalues in 1-by-1 blocks and any complex eigenvalues, lambda + i*mu, in 2-by-2 blocks, [lambda, mu; -mu, lambda]. The columns of V represent the eigenvectors in the sense that A*V = V*D, i.e. A.times(V) equals V.times(D). The matrix V may be badly conditioned, or even singular, so the validity of the equation A = V*D*inverse(V) depends upon V.cond().

Constructor & Destructor Documentation

Jama.EigenvalueDecomposition.EigenvalueDecomposition ( Matrix  Arg)

Check for symmetry, then construct the eigenvalue decomposition

Parameters
ASquare matrix
Returns
Structure to access D and V.

Member Function Documentation

Matrix Jama.EigenvalueDecomposition.getD ( )

Return the block diagonal eigenvalue matrix

Returns
D
double [] Jama.EigenvalueDecomposition.getImagEigenvalues ( )

Return the imaginary parts of the eigenvalues

Returns
imag(diag(D))
double [] Jama.EigenvalueDecomposition.getRealEigenvalues ( )

Return the real parts of the eigenvalues

Returns
real(diag(D))
Matrix Jama.EigenvalueDecomposition.getV ( )

Return the eigenvector matrix

Returns
V

The documentation for this class was generated from the following file: