SpecialFunctions (weka-dev 3.9.7 API)

java.lang.Object
- weka.core.SpecialFunctions

All Implemented Interfaces:

RevisionHandler
```
public final class SpecialFunctions
extends Object
implements RevisionHandler
```
Class implementing some mathematical functions.

Version:

$Revision$

Author:

Eibe Frank (eibe@cs.waikato.ac.nz)

Constructor Summary

Constructors
Constructor Description

SpecialFunctions()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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(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 String getRevision()
```
    Returns the revision string.
    
    Specified by:
    
    getRevision in interface RevisionHandler
    
    Returns:
    
    the revision
  - main
```
public static void main(String[] ops)
```
    Main method for testing this class.