Package org.ejml.simple

Class SimpleEVD<T extends SimpleBase>

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

    • Constructor Summary

      Constructors 
      Constructor Description
      SimpleEVD​(org.ejml.data.Matrix mat)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      org.ejml.data.Complex_F64 getEigenvalue​(int index)
      Returns an eigenvalue as a complex number.
      java.util.List<org.ejml.data.Complex_F64> getEigenvalues()
      Returns a list of all the eigenvalues
      T getEigenVector​(int index)
      Used to retrieve real valued eigenvectors.
      org.ejml.interfaces.decomposition.EigenDecomposition getEVD()
      Returns the underlying decomposition that this is a wrapper around.
      int getIndexMax()
      Returns the index of the eigenvalue which has the largest magnitude.
      int getIndexMin()
      Returns the index of the eigenvalue which has the smallest magnitude.
      int getNumberOfEigenvalues()
      Returns the number of eigenvalues/eigenvectors.
      double quality()
      Computes the quality of the computed decomposition.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • SimpleEVD

        public SimpleEVD​(org.ejml.data.Matrix mat)

    • Method Detail

      • getEigenvalues

        public java.util.List<org.ejml.data.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 org.ejml.data.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

        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 org.ejml.interfaces.decomposition.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.