org.jutil.math.matrix
Interface EigenvalueDecomposition

All Known Implementing Classes:

SchurEigenvalueDecomposition

public interface EigenvalueDecomposition

A class of eigenvalue decompositions of a matrix.

Field Summary
static java.lang.String	CVS_REVISION

 

Method Summary
abstract  double	getEigenvalue(int index)           Return the index'th eigenvalue.
abstract  Column	getEigenvalues()           Return the eigenvalues.
abstract  Column	getEigenvector(int index)           Return the index'th eigenvector.
abstract  Matrix	getEigenvectors()           Return the eigenvectors.
abstract  int	getNbEigenvalues()           Return the number of eigenvalues.
abstract  Matrix	lambda()           Return the eigenvalue matrix of this EigenvalueDecomposition.

 

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

lambda

public abstract Matrix lambda()

Return the eigenvalue matrix of this EigenvalueDecomposition.

Specifications:

public behavior
ensures \result != null;
ensures \result .isDiagonal();
ensures \result .getNbRows() == getNbEigenvalues();
ensures \result .isSquare();
ensures ( \forall int i; i >= 1&&i <= getNbEigenvalues(); \result .elementAt(i,i) == getEigenvalue(i));

getEigenvectors

public abstract Matrix getEigenvectors()

Return the eigenvectors.

Specifications:

public behavior
ensures \result != null;

getEigenvalues

public abstract Column getEigenvalues()

Return the eigenvalues.

Specifications:

public behavior
ensures \result != null;
ensures ( \forall int i; i >= 1&&i <= \result .size(); \result .elementAt(i) != 0);

getEigenvector

public abstract Column getEigenvector(int index)

Return the index'th eigenvector.

Parameters:

index - The index of the requested eigenvector.

Specifications:

public behavior
requires index >= 1;
requires index <= getNbEigenvalues();
ensures \result .equals(getEigenvectors().getColumn(index));

getEigenvalue

public abstract double getEigenvalue(int index)

Return the index'th eigenvalue.

Parameters:

index - The index of the requested eigenvalue.

Specifications:

public behavior
requires index >= 1;
requires index <= getNbEigenvalues();
ensures \result == getEigenvalues().elementAt(index);

getNbEigenvalues

public abstract int getNbEigenvalues()

Return the number of eigenvalues.

Specifications:

public behavior
ensures \result == getEigenvalues().size();