LISTING PROGRAM REGRESI

import java.util.Scanner;

class Regresi {

    Scanner input = new Scanner(System.in);

    double[] x;

    double[] y;

    double[] x2;

    double[] y2;

    double[] xy;

    int n;

    double a1,a0,b1,b0;

    public Regresi(){

                                                menu();}

                        public void menu(){

                        System.out.println("------------------");

                      System.out.println("| Menu Utama     |");

                      System.out.println("| 1. Input       |");

                      System.out.println("| 2. Regresi Y-X |");

                      System.out.println("| 3. Regresi X-Y |");

                     System.out.println("| 4. X-it        |");

                      System.out.println("------------------");

                      System.out.print("Masukkan Pilihanmu  : " );

                      int pil = input.nextInt();

                      switch(pil){

                                              case 1:

                                              clean();

                                            try{

                                                input();

                                            }catch(IndexOutOfBoundsException ex){

                                                System.out.println("Ada Kesalahan pada proses IO");}

                                              clean();

                                              menu();

                                               case 2:

                                             clean();

                                             regresiYX();

                                         menu();

                                         case 3:

                                             clean();

                                             regresiXY();

                                             menu();

                                         default:

                                        System.exit(0);}}

                         public void clean(){

                       for (int i=0;i<=20;i++){

                                              System.out.println("\n");} }

                        public void input(){

                                                System.out.print("masukan jumlah data :");

                                                n = input.nextInt();

                                                x= new double[n];

                                                y= new double[n];

                                                x2 = new double[n];

                                                y2=new double[n];

                                                xy=new double[n];

                                                System.out.print("\nmasukkan data x :\n");

                                                for(int i=0;i<n;i++){

                                                                        System.out.print("data ke-"+(i+1)+":");

                                                                        x[i]= input.nextInt();}

                                               

                                                System.out.println("\nmasukkan data y :");

                                                for(int i=0;i<n;i++){

                                                                        System.out.print("data ke-"+(i+1)+":");

                                                                        y[i]= input.nextInt();}

                           for(int i=0 ; i<n;i++) {

                                               x2[i]=Math.pow(x[i],2);

                                               y2[i]=Math.pow(y[i],2);

                                               xy[i]= x[i] * y[i] ;}}

                        public double sigma(double k[]){

                           double data = 0;

        for(int i=0; i<n;i++) {

                      data = data + k[i]; }

       return(data); }

    

public void regresiYX(){

     a1 = ((n*sigma(xy)) - (sigma(x) * sigma(y))) / ((n*sigma(x2))-Math.pow(sigma(x),2));

     a0 = ((sigma(y) * sigma(x2)) - (sigma(x) * sigma(xy))) / ((n*sigma(x2))-Math.pow(sigma(x),2));

     System.out.println("Persamaan Regrsi Y terhadap X");

     if (a1> 0)

     System.out.println("Y = "+a0+" + "+a1+"x");

     else

     System.out.println("Y = "+a0+a1+ "x"); }

    

     public void regresiXY(){

      b1 = ((n*sigma(xy)) - (sigma(y) * sigma(x))) / ((n*sigma(y2))-Math.pow(sigma(y),2));

      b0 = ((sigma(x) * sigma(y2)) - sigma(y) * sigma(xy)) / (n* sigma(y2)-Math.pow(sigma(y),2));

      System.out.println("Persamaan Regresi X terhadap Y");

      if (b1>0)

      System.out.println("X = "+b0+" + "+b1+"x");

      else

    System.out.println("X = "+b0+b1+"x");  }

                       

public static void main(String[] args) {

                                                new Regresi();}}