fork download
copy 
  1. class Main {
  2.     public static void main(String[] args) {
  3.         double[] x = {0, 1, 2, 3};
  4.         double[] y = {1, 2, 4, 8};
  5.         double x0 = 1.5;
  6.         double result = newtonForward(x, y, x0);
  7.         System.out.printf("Interpolated value at x = %.2f is y = %.3f\n", x0, result);
  8.     }
  9.     static double newtonForward(double[] x, double[] y, double x0) {
  10.         int n = x.length;
  11.         double[][] diff = new double[n][n];
  12.  
  13.         for (int i = 0; i < n; i++)
  14.             diff[i][0] = y[i];
  15.  
  16.         for (int j = 1; j < n; j++)
  17.             for (int i = 0; i < n - j; i++)
  18.                 diff[i][j] = diff[i + 1][j - 1] - diff[i][j - 1];
  19.  
  20.         double h = x[1] - x[0];
  21.         double u = (x0 - x[0]) / h;
  22.         double sum = diff[0][0];
  23.         double term = 1;
  24.         for (int i = 1; i < n; i++) {
  25.             term *= (u - (i - 1));
  26.             sum += term * diff[0][i] / fact(i);
  27.         }
  28.          return sum;  }
  29.        static int fact(int n) {
  30.         int f = 1;
  31.         for (int i = 1; i <= n; i++) f *= i;
  32.         return f;
  33.     }
  34. }
  35.  
Success #stdin #stdout 0.15s 56172KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Interpolated value at x = 1.50 is y = 2.813
https://ideone.com/qXqJHo
language:
Java (HotSpot 12)
created:
14 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!