Package elki.math.linearalgebra.pca.filter

Class WeakEigenPairFilter

  • All Implemented Interfaces:
    EigenPairFilter
    @Title("Weak Eigenpair Filter")
@Description("Sorts the eigenpairs in decending order of their eigenvalues and returns those eigenpairs, whose eigenvalue is above the average (\'expected\') eigenvalue.")
public class WeakEigenPairFilter
extends java.lang.Object
implements EigenPairFilter
    The WeakEigenPairFilter sorts the eigenpairs in descending order of their eigenvalues and returns the first eigenpairs who are above the average mark as "strong", the others as "weak".
    Since:
    0.2
    Author:
    Erich Schubert

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  WeakEigenPairFilter.Par
      Parameterization class.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static double DEFAULT_WALPHA
      The default value for walpha.
      private double walpha
      The noise tolerance level for weak eigenvectors

    • Constructor Summary

      Constructors 
      Constructor Description
      WeakEigenPairFilter​(double walpha)
      Constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int filter​(double[] eigenValues)
      Filters the specified eigenvalues into strong and weak eigenvalues, where strong eigenvalues have high variance and weak eigenvalues have small variance.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • DEFAULT_WALPHA

        public static final double DEFAULT_WALPHA
        The default value for walpha.
        See Also:
        Constant Field Values

      • walpha

        private double walpha
        The noise tolerance level for weak eigenvectors

    • Constructor Detail

      • WeakEigenPairFilter

        public WeakEigenPairFilter​(double walpha)
        Constructor.
        Parameters:
        walpha -

    • Method Detail

      • filter

        public int filter​(double[] eigenValues)
        Description copied from interface: EigenPairFilter
        Filters the specified eigenvalues into strong and weak eigenvalues, where strong eigenvalues have high variance and weak eigenvalues have small variance.
        Specified by:
        filter in interface EigenPairFilter
        Parameters:
        eigenValues - the array of eigenvalues, must be sorted descending
        Returns:
        the number of eigenvectors to keep