Package org.ejml.simple

Class SimpleEVD<T extends SimpleBase>

java.lang.Object
org.ejml.simple.SimpleEVD<T>
public class SimpleEVD<T extends SimpleBase> extends Object
Wrapper around EigenDecomposition for SimpleMatrix

  • Constructor Details

    • SimpleEVD

      public SimpleEVD(Matrix mat)

  • Method Details

    • getEigenvalues

      public List<Complex_F64> getEigenvalues()
      Returns a list of all the eigenvalues

    • getNumberOfEigenvalues

      public int getNumberOfEigenvalues()
      Returns the number of eigenvalues/eigenvectors. This is the matrix's dimension.
      Returns:
      number of eigenvalues/eigenvectors.

    • getEigenvalue

      public Complex_F64 getEigenvalue(int index)

      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.

      Parameters:
      index - Index of the eigenvalue eigenvector pair.
      Returns:
      An eigenvalue.

    • getEigenVector

      @Nullable public T getEigenVector(int index)

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

      Parameters:
      index - Index of the eigenvalue eigenvector pair.
      Returns:
      If the associated eigenvalue is real then an eigenvector is returned, null otherwise.

    • quality

      public double quality()

      Computes the quality of the computed decomposition. A value close to or less than 1e-15 is considered to be within machine precision.

      This function must be called before the original matrix has been modified or else it will produce meaningless results.

      Returns:
      Quality of the decomposition.

    • getEVD

      public EigenDecomposition getEVD()
      Returns the underlying decomposition that this is a wrapper around.
      Returns:
      EigenDecomposition

    • getIndexMax

      public int getIndexMax()
      Returns the index of the eigenvalue which has the largest magnitude.
      Returns:
      index of the largest magnitude eigen value.

    • getIndexMin

      public int getIndexMin()
      Returns the index of the eigenvalue which has the smallest magnitude.
      Returns:
      index of the smallest magnitude eigen value.