GiniSplitMetric

java.lang.Object
- weka.classifiers.trees.ht.SplitMetric
- - weka.classifiers.trees.ht.GiniSplitMetric

All Implemented Interfaces:

java.io.Serializable
```
public class GiniSplitMetric
extends SplitMetric
implements java.io.Serializable
```
Implements the gini splitting criterion

Version:

$Revision: 9720 $

Author:

Richard Kirkby (rkirkby@cs.waikato.ac.nz), Mark Hall (mhall{[at]}pentaho{[dot]}com)

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

GiniSplitMetric()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double`	`evaluateSplit(java.util.Map<java.lang.String,WeightMass> preDist, java.util.List<java.util.Map<java.lang.String,WeightMass>> postDist)`	Evaluate the merit of a split
`double`	`getMetricRange(java.util.Map<java.lang.String,WeightMass> preDist)`	Get the range of the splitting metric
`static double`	`gini(java.util.Map<java.lang.String,WeightMass> dist)`	Return the gini metric computed from the supplied distribution

Methods inherited from class weka.classifiers.trees.ht.SplitMetric
sum

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - GiniSplitMetric
```
public GiniSplitMetric()
```
- Method Detail
  - evaluateSplit
```
public double evaluateSplit(java.util.Map<java.lang.String,WeightMass> preDist,
                            java.util.List<java.util.Map<java.lang.String,WeightMass>> postDist)
```
    Description copied from class: SplitMetric
    
    Evaluate the merit of a split
    
    Specified by:
    
    evaluateSplit in class SplitMetric
    
    Parameters:
    
    preDist - the class distribution before the split
    
    postDist - the class distributions after the split
    
    Returns:
    
    the merit of the split
  - gini
```
public static double gini(java.util.Map<java.lang.String,WeightMass> dist)
```
    Return the gini metric computed from the supplied distribution
    
    Parameters:
    
    dist - dist the distribution to compute the gini metric from
    
    Returns:
  - getMetricRange
```
public double getMetricRange(java.util.Map<java.lang.String,WeightMass> preDist)
```
    Description copied from class: SplitMetric
    
    Get the range of the splitting metric
    
    Specified by:
    
    getMetricRange in class SplitMetric
    
    Parameters:
    
    preDist - the pre-split class distribution
    
    Returns:
    
    the range of the splitting metric