no.uib.cipr.matrix

Class SymmTridiagEVD

java.lang.Object

no.uib.cipr.matrix.SymmTridiagEVD

public class SymmTridiagEVD
extends Object

Computes eigenvalues of symmetrical, tridiagonal matrices

Constructor Summary

Constructors

Constructor and Description
SymmTridiagEVD(int n) Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices.
SymmTridiagEVD(int n, boolean vectors) Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices.
SymmTridiagEVD(int n, boolean vectors, double abstol) Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices
SymmTridiagEVD(int n, double abstol) Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices.

Method Summary

Modifier and Type	Method and Description
SymmTridiagEVD	factor(SymmTridiagMatrix A) Computes the eigenvalue decomposition of the given matrix
static SymmTridiagEVD	factorize(Matrix A) Convenience method for computing the full eigenvalue decomposition of the given matrix
double[]	getEigenvalues() Gets the eigenvalues (stored in ascending order)
DenseMatrix	getEigenvectors() Gets the eigenvectors, if available
boolean	hasEigenvectors() True if the eigenvectors have been computed

Methods inherited from class java.lang.Object

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

Constructor Detail

SymmTridiagEVD

public SymmTridiagEVD(int n)

Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices. Computes all eigenvalues and eigenvectors, and uses a low default tolerance criteria

Parameters:

n - Size of the matrix

SymmTridiagEVD

public SymmTridiagEVD(int n,
                      double abstol)

Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices. Computes all eigenvalues and eigenvectors

Parameters:

n - Size of the matrix

abstol - Absolute tolerance criteria

SymmTridiagEVD

public SymmTridiagEVD(int n,
                      boolean vectors)

Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices. Uses a low default tolerance criteria

Parameters:

n - Size of the matrix

vectors - True to compute the eigenvectors, false for just the eigenvalues

SymmTridiagEVD

public SymmTridiagEVD(int n,
                      boolean vectors,
                      double abstol)

Sets up an eigenvalue decomposition for symmetrical, tridiagonal matrices

Parameters:

n - Size of the matrix

vectors - True to compute the eigenvectors, false for just the eigenvalues

abstol - Absolute tolerance criteria

Method Detail

factorize

public static SymmTridiagEVD factorize(Matrix A)
                                throws NotConvergedException

Convenience method for computing the full eigenvalue decomposition of the given matrix

Parameters:

A - Matrix to factorize. Main diagonal and superdiagonal is copied, and the matrix is not modified

Returns:

Newly allocated decomposition

Throws:

NotConvergedException

factor

public SymmTridiagEVD factor(SymmTridiagMatrix A)
                      throws NotConvergedException

Computes the eigenvalue decomposition of the given matrix

Parameters:

A - Matrix to factorize. Overwritten on return

Returns:

The current eigenvalue decomposition

Throws:

NotConvergedException

getEigenvalues

public double[] getEigenvalues()

Gets the eigenvalues (stored in ascending order)

getEigenvectors

public DenseMatrix getEigenvectors()

Gets the eigenvectors, if available

hasEigenvectors

public boolean hasEigenvectors()

True if the eigenvectors have been computed