programming-examples/java/To implement Na‹ve Bayesian Classifier.java
2019-11-18 13:43:20 +01:00

155 lines
5.1 KiB
Java

import java.util.*;
class btheo
{
static char outlook[]= {'S','S','O','R','R','R','O','S','S','R','S','O','O','R'};
static char temperature[]= {'H','H','H','M','C','C','C','M','C','M','M','M','H','M'};
static char humidity[]= {'P','P','P','P','N','N','N','P','N','N','N','P','N','P'};
static char windy[]= {'F','T','F','F','F','T','T','F','F','F','T','T','F','T'};
static char class1[]= {'N','N','P','P','P','N','P','N','P','P','P','P','P','N'};
static double prob[][]=new double[4][2];
static double pp=9.0/14.0;
static double npp=5.0/14.0;
static int flag=0;
static int flag1=0;
static double play_N=1;
static double notplay_N=1;
static void cal_N(int a)
{
if(a==1)
{
for(int i=0; i<4; ++i)
play_N*=prob[i][0];
play_N*=pp;
//System.out.println("\nValue of N of play \n"+play_N);
}
Else
{
for(int i=0; i<4; ++i)
notplay_N*=prob[i][1
notplay_N*=npp;
//System.out.println("\nValue of N of No play \n"+notplay_N);
}
}
static double cal_play_prob(char ch)
{
double prob=0;
double count=0;
if(flag==0)
{
for(int i=0; i<14; ++i)
if(outlook[i]==ch && class1[i]=='P')
++count;
prob=count/9.0;
flag=1;
}
else if
(flag==1)
{
for(int i=0; i<14; ++i)
if(temperature[i]==ch && class1[i]=='P')
++count;
prob=count/9.0;
flag=2;
}
else if
(flag==2)
{
for(int i=0; i<14; ++i)
if(humidity[i]==ch && class1[i]=='P')
++count;
prob=count/9.0;
flag=3;
}
else if(flag==3)
{
for(int i=0; i<14; ++i)
if(windy[i]==ch && class1[i]=='P')
++count;
prob=count/9.0;
}
return prob;
}
static double cal_noplay_prob(char ch)
{
double prob=0;
double count=0;
if(flag1==0)
{
for(int i=0; i<14; ++i)
if(outlook[i]==ch && class1[i]=='N')
++count;
prob=count/5.0;
flag1=1;
}
else if(flag1==1)
{
for(int i=0; i<14; ++i)
if(temperature[i]==ch && class1[i]=='N')
++count;
prob=count/5.0;
flag1=2;
}
else if(flag1==2)
{
for(int i=0; i<14; ++i)
if(humidity[i]==ch && class1[i]=='N')
++count;
prob=count/5.0;
flag1=3;
}
else if(flag1==3)
{
for(int i=0; i<14; ++i)
if(windy[i]==ch && class1[i]=='N')
++count;
prob=count/5.0;
}
return prob;
}
public static void main(String args[])
{
Scanner scr=new Scanner(System.in);
System.out.println("Table\n");
System.out.println("Outlook\t Temperature\t Humidity\t Windy \tClass");
for(int i=0; i<14; ++i)
{
System.out.print(outlook[i]+"\t\t"+temperature[i]+"\t\t"+humidity[i]+"\t\t"+windy[i]+"\t\t"+class1[i]);
System.out.println();
}
System.out.println("Menu:\nOutlook: Sunny=S Overcast=O Rain=R\tTemperature: Hot=H Mild=M Cool=C\n");
System.out.println("Humidity: Peak=P Normal=N\t\tWindy: True=T False=F\n\nYour input should belong to one of these classes.\n");
System.out.println("class1: Play=P class2:Not Play=NP");
System.out.println("\nEnter your input: example. t={rain,hot,peak,false} input will be R,H,P,F");
String s=scr.nextLine();
char ch;
int count=0;
for(int i=0; i<8; i+=2)
{
ch=s.charAt(i);
prob[count][0]=cal_play_prob(ch);
prob[count][1]=cal_noplay_prob(ch);
++count;
}
cal_N(1);
cal_N(2);
double pt=play_N+notplay_N;
double prob_of_play=0;
double prob_of_noplay=0;
prob_of_play=play_N/pt;
prob_of_noplay=notplay_N/pt;
System.out.println("\nProbability of play "+prob_of_play);
System.out.println("\nProbability of NO play "+prob_of_noplay );
if(prob_of_play>prob_of_noplay)
System.out.println("\nThe new tuple classified under \"PLAY\" category.Hence there will be play!!!");
else
System.out.println("\nThe new tuple classified under \"NO PLAY\" category.Hence there will be NO play.");
}
}
}