org.jutil.math.matrix
Interface EigenvalueDecomposition

All Known Implementing Classes:

SchurEigenvalueDecomposition

public interface EigenvalueDecomposition

A class of eigenvalue decompositions of a matrix.

Version:

$Revision: 1.3 $

Author:

Marko van Dooren

Field Summary

static java.lang.String

CVS_REVISION

Method Summary

double	getEigenvalue(int index) public behavior pre index >= 1; pre index <= getNbEigenvalues(); post \result == getEigenvalues().elementAt(index); Return the index'th eigenvalue.
Column	getEigenvalues() public behavior post \result != null; post (\forall int i; i>=1 && i<=getNbEigenvalues(); \result.elementAt(i) != 0); Return the eigenvalues.
Column	getEigenvector(int index) public behavior pre index >= 1; pre index <= getNbEigenvalues(); post \result.equals(getEigenvectors.getColumn(index)); Return the index'th eigenvector.
Matrix	getEigenvectors() public behavior post \result != null; Return the eigenvectors.
int	getNbEigenvalues() public behavior post \result > 0; Return the number of eigenvalues.
Matrix	lambda() public behavior post \result != null; post \result.isDiagonal(); post (\forall int i; i>=1 && i <= getNbEigenValues(); \result.elementAt(i,i) == getEigenvalue(i)); Return the eigenvalue matrix of this EigenvalueDecomposition.

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

Method Detail

lambda

public Matrix lambda()

public behavior

post \result != null;
post \result.isDiagonal();
post (\forall int i; i>=1 && i <= getNbEigenValues();
\result.elementAt(i,i) == getEigenvalue(i));
Return the eigenvalue matrix of this EigenvalueDecomposition.

getEigenvectors

public Matrix getEigenvectors()

public behavior

post \result != null;
Return the eigenvectors.

getEigenvalues

public Column getEigenvalues()

public behavior

post \result != null;
post (\forall int i; i>=1 && i<=getNbEigenvalues();
\result.elementAt(i) != 0);
Return the eigenvalues.

getEigenvector

public Column getEigenvector(int index)

public behavior

pre index >= 1;
pre index <= getNbEigenvalues();

post \result.equals(getEigenvectors.getColumn(index));
Return the index'th eigenvector.

Parameters:

index - The index of the requested eigenvector.

getEigenvalue

public double getEigenvalue(int index)

public behavior

pre index >= 1;
pre index <= getNbEigenvalues();

post \result == getEigenvalues().elementAt(index);
Return the index'th eigenvalue.

Parameters:

index - The index of the requested eigenvalue.

getNbEigenvalues

public int getNbEigenvalues()

public behavior

post \result > 0;
Return the number of eigenvalues.