Naive Bayes Classifier Construction

NaiveBayesConstructor.java

//constructs a naive Bayes binary classifier
public NaiveBayes(double in[][], boolean out[]){
   int inputs = in[0].length ;
   //initialize sums and sums of squares for each class
   double[] poss = new double[inputs], poss2 = new double[inputs];
   double[] negs = new double[inputs], negs2 = new double[inputs];
   //calculate amount of each class, sums, and sums of squares
   for(int k=0;k<in.length;k++){//for each data point
      if(out[k]){
         positives++;//keep track of total positives
         for(int j=0;j<inputs;j++){//for each input
            poss[j] += in[k][j] ;
            poss2[j] += in[k][j]*in[k][j] ;
         }
      }else{
         negatives++;//keep track of total negatives
         for(int j=0;j<inputs;j++){//for each input
            negs[j] += in[k][j] ;
            negs2[j] += in[k][j]*in[k][j] ;
         }
      }
   }
   //initialize means and variances
   posmean = new double[inputs] ;
   posvariance = new double[inputs] ;
   negmean = new double[inputs] ;
   negvariance = new double[inputs] ;
   //calculate means and variances
   for(int j=0;j<inputs;j++){//for each input
      posmean[j] = poss[j]/positives;
      negmean[j] = negs[j]/negatives;
      posvariance[j] = (poss2[j] - ((poss[j]*poss[j])/positives))/(positives - 1) ;
      negvariance[j] = (negs2[j] - ((negs[j]*negs[j])/negatives))/(negatives - 1) ;
   }
}