distributions.ClassdistributionNominal.java Source code

Introduction

Here is the source code for distributions.ClassdistributionNominal.java

Source

/*
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 */
package distributions;

import weka.core.Instance;
import weka.core.Instances;

/**
 *
 * @author Thierry
 */

/**
*diese Klasse wird fr die Berechnung der Warscheinlichkeit eine Nominale Variable
* in Abhngigkeit einer bestimmte Klassenwert verwendet 
* Diese Klasse benutz das Interface Distribution
* parameter: Inst: die Trainingsmenge
* classID: der Index der Klassenwert; conditionalprobs:Array zum speichern der bedingte Warscheinlichkeiten
* attindexen: Array zur Speicherung der Attributindexen der Trainingsmenge
* kID:index des Attributs
 */

public class ClassdistributionNominal implements Distribution {

    private Instances inst;

    /** den ClaassenattributIndex*/
    int classID;

    /*das elternid*/
    private int kID;

    /*table von bedigte Wahrscheinlichkeiten*/
    private double[] conditionalprobs;

    /*die attributeindexen*/
    private int[] attindexen;

    /**
    Konstruktor 
         * @param inst
         * @param classID
         * @param kID
    */
    public ClassdistributionNominal(Instances inst, int classID, int kID) {
        this.inst = new Instances(inst);
        this.classID = classID;
        this.kID = kID;
        conditionalprobs = new double[inst.attribute(kID).numValues()];
        attindexen = new int[inst.attribute(kID).numValues()];
        for (int i = 0; i < attindexen.length; i++) {
            attindexen[i] = i;
        }

    }

    /**
     * Procedur zur Berechnung der Bedingtewahrscheinlichkeiten
     */
    @Override

    public void calculateProbs() {
        for (int i = 0; i < inst.numInstances(); i++) {

            for (int k = 0; k < attindexen.length; k++) {

                if (inst.instance(i).classValue() == classID) {
                    if ((inst.instance(i).value(kID)) == (attindexen[k])) {
                        conditionalprobs[k]++;
                    }
                }
            }
        }

        int count = 0;
        for (int j = 0; j < inst.numInstances(); j++) {
            if (inst.instance(j).classValue() == classID) {
                count++;
            }
        }

        for (int i = 0; i < conditionalprobs.length; i++) {

            if (count != 0)
                ;
            conditionalprobs[i] /= count;
        }
    }

    /**
     *
     * @param <Object>
     * @param insta
     * @return
     *  Rckgabe der berechnete Bedingtewahrscheinlichkeiten
     */
    @Override

    public <Object> double getProbs(Object insta) {
        calculateProbs();
        int a = (int) ((Instance) insta).value(kID);

        return conditionalprobs[a];

    }

    @Override
    public double[][] numberOfcounts() {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

}