NAIVE BAYESIAN CLASSIFICATION

JAVA PROGRAM CODE :

import java.io.*;

import java.math.*;

class Bayes

{       BufferedReader sc=new BufferedReader(newInputStreamReader(System.in));

        int i;

        double y1,y2;

        double c=0.0,c1=0.0,c3=0.0,c4,c5=0.0,c6;

  String a[][]={{"y","h","n","f","n"},{"y","h","n","e","n"},{"m_a","h","n","f","y"},{"s","m","n","f","y"},{"s","l","y","f","y"},{"s","l","y","e","n"},{"m_a","l","y","e","y"},{"y","m","n","f","n"},{"y","l","y","f","y"},{"s","m","y","f","y"},{"y","m","y","e","y"},{"m_a","m","n","e","y"},{"m_a","h","y","f","y"},{"s","m","n","e","n"},};

         void start1() throws Exception

        {

                System.out.println("Enter the conditions to see whether can buy computer or not ");

                System.out.println("Enter age : ");

                String x1=sc.readLine();

                System.out.println("Enter income : ");

                String x2=sc.readLine();

                System.out.println("Enter student y or n: ");

                String x3=sc.readLine();

                System.out.println("Enter credit rating: ");

                String x4=sc.readLine();

                entropy();

                double a1=atto(x1,0);

                System.out.println("P("+x1+"/y) = " +a1);

                double a2=atto(x2,1);

                System.out.println("P("+x2+"/y) = " +a2);

                double a3=atto(x3,2);

                System.out.println("P("+x3+"/y) = " +a3);

                double a4=atto(x4,3);

                System.out.println("P("+x4+"/y) = " +a4);

                double b1=atto1(x1,0);

                System.out.println("P("+x1+"/n) = " +b1);

                double b2=atto1(x2,1);

                System.out.println("P("+x2+"/n) = " +b2);

                double b3=atto1(x3,2);

                System.out.println("P("+x3+"/n) = " +b3);

                double b4=atto1(x4,3);

                System.out.println("P("+x4+"/n) = " +b4);

                double p1=(a1*a2*a3*a4);

                System.out.println("P(X/y) = " +p1);

                double p2=(b1*b2*b3*b4);

                System.out.println("P(X/n) = " +p2);

                p1=(p1*y1);

                System.out.println("P(y/X) = " +p1);

                p2=(p2*y2);

                System.out.println("P(n/X) = " +p2);

                if(p1>p2)

                {     System.out.println("You Can buy computer");

                }

                else

                {      System.out.println("You Can't buy computer");

                }

        }

        void entropy()

        {      c1=0.0;

                for(i=0;i<14 data-blogger-escaped-i="" data-blogger-escaped-o:p="">

                {

                        if(a[i][4].equals("y"))

                        c++;

                }

                c1=14-c;

                y1=(c/14.0);

                y2=(c1/14.0);

                System.out.println("P(y):"+ y1);

                System.out.println("P(n):"+ y2);

        }

        double atto(String at,int z)

        {      c3=0.0;

                for(i=0;i<14 data-blogger-escaped-i="" data-blogger-escaped-o:p="">

                {

                        if(a[i][z].equals(at))

                        {

                                if(a[i][4].equals("y"))

                                        c3++;

                        }

                }

                return((c3/c));

        }

        double atto1(String at1,int z1)

        {      c4=0.0;

                for(i=0;i<14 data-blogger-escaped-i="" data-blogger-escaped-o:p="">

                {

                        if(a[i][z1].equals(at1))

                        {

                                if(a[i][4].equals("n"))

                                        c4++;

                        }      

                }

                return((c4/c1));

        }

}

class Bayesmain1

{       public static void main(String args[]) throws Exception

        {      Bayes d=new Bayes();

                d.start1();

        }

}

OUTPUT :