Implement Gaussian Naive Bayes

Question

Ich versuche, Gaussian Naive Bayes in C# für die Klassifizierung von Punkten zu implementieren. Ich habe implementiert ersten Teil (http://www.statsoft.com/textbook/naive-bayes-classifier/) Wahrscheinlichkeit Teil, aber ich verstehe nicht, wie Gauß Naive Bayes Algorithmus normales Modell zu implementieren. Dies ist mein Code:

class NaiveBayesClassifier 
    { 
     private List<Point> listTrainPoints = new List<Point>(); 
     private int totalPoints = 0; 

     public NaiveBayesClassifier(List<Point> listTrainPoints) 
     { 
      this.listTrainPoints = listTrainPoints; 
      this.totalPoints = this.listTrainPoints.Count; 
     } 

     private List<Point> vecinityPoints(Point p, double maxDist) 
     { 
      List<Point> listVecinityPoints = new List<Point>(); 
      for (int i = 0; i < listTrainPoints.Count; i++) 
      { 
       if (p.distance(listTrainPoints[i]) <= maxDist) 
       { 
        listVecinityPoints.Add(listTrainPoints[i]); 
       } 
      } 
      return listVecinityPoints; 
     } 

     public double priorProbabilityFor(double currentType) 
     { 
      double countCurrentType = 0; 
      for (int i = 0; i < this.listTrainPoints.Count; i++) 
      { 
       if (this.listTrainPoints[i].Type == currentType) 
       { 
        countCurrentType++; 
       } 
      } 

      return (countCurrentType/this.totalPoints); 
     } 

     public double likelihoodOfXGiven(double currentType, List<Point> listVecinityPoints) 
     { 
      double countCurrentType = 0; 
      for (int i = 0; i < listVecinityPoints.Count; i++) 
      { 
       if (listVecinityPoints[i].Type == currentType) 
       { 
        countCurrentType++; 
       } 
      } 

      return (countCurrentType/this.totalPoints); 
     } 

     public double posteriorProbabilityXBeing(double priorProbabilityFor, double likelihoodOfXGiven) 
     { 
      return (priorProbabilityFor * likelihoodOfXGiven); 
     } 

     public int allegedClass(Point p, double maxDist) 
     { 
      int type1 = 1, type2 = 2; 

      List<Point> listVecinityPoints = this.vecinityPoints(p, maxDist); 

      double priorProbabilityForType1 = this.priorProbabilityFor(type1); 
      double priorProbabilityForType2 = this.priorProbabilityFor(type2); 

      double likelihoodOfXGivenType1 = likelihoodOfXGiven(type1, listVecinityPoints); 
      double likelihoodOfXGivenType2 = likelihoodOfXGiven(type2, listVecinityPoints); 

      double posteriorProbabilityXBeingType1 = posteriorProbabilityXBeing(priorProbabilityForType1, likelihoodOfXGivenType1); 
      double posteriorProbabilityXBeingType2 = posteriorProbabilityXBeing(priorProbabilityForType2, likelihoodOfXGivenType2); 

      if (posteriorProbabilityXBeingType1 > posteriorProbabilityXBeingType2) 
       return type1; 
      else 
       return type2; 
     } 
    } 

In dieser pdf-Datei (Problem 5) ist die Beschreibung dessen, was ich tun muss (http://romanager.ro/s.10-701.hw1.sol.pdf). Meine Arbeit besteht darin, Gaussina Naive Bayes und kNN Algorithmen zu implementieren und das Ergebnis mit einer Reihe von Daten zu vergleichen. Bitte bringen Sie mir bei, wo und wie Gauß'sche Naive Bayes Algorithmen implementiert werden.

Danke!

Answer 1

gutes Beispiel hier:

look at sex predictor at bottom of this page as an example with a real data set

Gute Erklärung hier:

naive bayes breakdown on stackoverflow