Package org.ejml.dense.row.decomposition.eig

Class SwitchingEigenDecomposition_DDRM

java.lang.Object
org.ejml.dense.row.decomposition.eig.SwitchingEigenDecomposition_DDRM
All Implemented Interfaces:
DecompositionInterface<DMatrixRMaj>, EigenDecomposition<DMatrixRMaj>, EigenDecomposition_F64<DMatrixRMaj>
public class SwitchingEigenDecomposition_DDRM extends Object implements EigenDecomposition_F64<DMatrixRMaj>
Checks to see what type of matrix is being decomposed and calls different eigenvalue decomposition algorithms depending on the results. This primarily checks to see if the matrix is symmetric or not.

  • Constructor Details

    • SwitchingEigenDecomposition_DDRM

      public SwitchingEigenDecomposition_DDRM(int matrixSize, boolean computeVectors, double tol)
      Parameters:
      tol - Tolerance for a matrix being symmetric

    • SwitchingEigenDecomposition_DDRM

      public SwitchingEigenDecomposition_DDRM(EigenDecomposition_F64<DMatrixRMaj> symmetricAlg, EigenDecomposition_F64<DMatrixRMaj> generalAlg, double tol)

    • SwitchingEigenDecomposition_DDRM

      public SwitchingEigenDecomposition_DDRM(int matrixSize)

  • Method Details

    • getNumberOfEigenvalues

      public int getNumberOfEigenvalues()
      Description copied from interface: EigenDecomposition
      Returns the number of eigenvalues/eigenvectors. This is the matrix's dimension.
      Specified by:
      getNumberOfEigenvalues in interface EigenDecomposition<DMatrixRMaj>
      Returns:
      number of eigenvalues/eigenvectors.

    • getEigenvalue

      public Complex_F64 getEigenvalue(int index)
      Description copied from interface: EigenDecomposition_F64

      Returns an eigenvalue as a complex number. For symmetric matrices the returned eigenvalue will always be a real number, which means the imaginary component will be equal to zero.

      NOTE: The order of the eigenvalues is dependent upon the decomposition algorithm used. This means that they may or may not be ordered by magnitude. For example the QR algorithm will returns results that are partially ordered by magnitude, but this behavior should not be relied upon.

      Specified by:
      getEigenvalue in interface EigenDecomposition_F64<DMatrixRMaj>
      Parameters:
      index - Index of the eigenvalue eigenvector pair.
      Returns:
      An eigenvalue.

    • getEigenVector

      public DMatrixRMaj getEigenVector(int index)
      Description copied from interface: EigenDecomposition

      Used to retrieve real valued eigenvectors. If an eigenvector is associated with a complex eigenvalue then null is returned instead.

      Specified by:
      getEigenVector in interface EigenDecomposition<DMatrixRMaj>
      Parameters:
      index - Index of the eigenvalue eigenvector pair.
      Returns:
      If the associated eigenvalue is real then an eigenvector is returned, null otherwise.

    • decompose

      public boolean decompose(DMatrixRMaj orig)
      Description copied from interface: DecompositionInterface
      Computes the decomposition of the input matrix. Depending on the implementation the input matrix might be stored internally or modified. If it is modified then the function DecompositionInterface.inputModified() will return true and the matrix should not be modified until the decomposition is no longer needed.
      Specified by:
      decompose in interface DecompositionInterface<DMatrixRMaj>
      Parameters:
      orig - The matrix which is being decomposed. Modification is implementation dependent.
      Returns:
      Returns if it was able to decompose the matrix.

    • inputModified

      public boolean inputModified()
      Description copied from interface: DecompositionInterface
      Checks if the input matrix to DecompositionInterface.decompose(org.ejml.data.Matrix) is modified during the decomposition process.
      Specified by:
      inputModified in interface DecompositionInterface<DMatrixRMaj>
      Returns:
      true if the input matrix to decompose() is modified.