Package weka.core

Class SpecialFunctions

  • All Implemented Interfaces:
    RevisionHandler

    public final class SpecialFunctions
    extends java.lang.Object
    implements RevisionHandler
    Class implementing some mathematical functions.
    Version:
    $Revision: 1.8 $
    Author:
    Eibe Frank (eibe@cs.waikato.ac.nz)
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String getRevision()
      Returns the revision string.
      static double lnFactorial​(double x)
      Returns natural logarithm of factorial using gamma function.
      static double log2Binomial​(double a, double b)
      Returns base 2 logarithm of binomial coefficient using gamma function.
      static double log2Multinomial​(double a, double[] bs)
      Returns base 2 logarithm of multinomial using gamma function.
      static void main​(java.lang.String[] ops)
      Main method for testing this class.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • SpecialFunctions

        public SpecialFunctions()
    • Method Detail

      • lnFactorial

        public static double lnFactorial​(double x)
        Returns natural logarithm of factorial using gamma function.
        Parameters:
        x - the value
        Returns:
        natural logarithm of factorial
      • log2Binomial

        public static double log2Binomial​(double a,
                                          double b)
        Returns base 2 logarithm of binomial coefficient using gamma function.
        Parameters:
        a - upper part of binomial coefficient
        b - lower part
        Returns:
        the base 2 logarithm of the binominal coefficient a over b
      • log2Multinomial

        public static double log2Multinomial​(double a,
                                             double[] bs)
        Returns base 2 logarithm of multinomial using gamma function.
        Parameters:
        a - upper part of multinomial coefficient
        bs - lower part
        Returns:
        multinomial coefficient of a over the bs
      • getRevision

        public java.lang.String getRevision()
        Returns the revision string.
        Specified by:
        getRevision in interface RevisionHandler
        Returns:
        the revision
      • main

        public static void main​(java.lang.String[] ops)
        Main method for testing this class.