C++ Program to Generate Forward Difference Table (with Output)

Table of Contents

• C++ Program
• Program Output
• Recommended Readings

While interpolating unknown value of dependent variable corresponding to some independent variable using Newton's Forward Interpolation formula we need to construct Forward Difference Table.

In this article, we are going to generate forward difference table using C++ programming language and output of program is also provided.

C++ Source Code: Forward Difference Table

#include<iostream>

using namespace std;

int main()
{
 float x[20], y[20][20];
 int i,j, n;

 /* Input Section */
 cout << "Enter number of data? " << endl;
 cin >> n;

 cout << "Enter data: " << endl;
 for(i = 0; i < n ; i++)
 {
  cout << "x[" << i << "] = ";
  cin >> x[i];
  cout << "y[" << i <<"] = ";
  cin >> y[i][0];
 }

 /* Generating Forward Difference Table */
 for(i = 1; i < n; i++)
 {
  for(j = 0; j < n-i; j++)
  {
   y[j][i] = y[j+1][i-1] - y[j][i-1];
  }
 }

 /* Displaying Forward Difference Table */
 cout << endl << "FORWARD DIFFERENCE TABLE" << endl;
 for(i = 0; i < n; i++)
 {
  cout << x[i];
  for(j = 0; j < n-i ; j++)
  {
   cout << "\t" << y[i][j];
  }
  cout << endl;
 }

 return 0;
}

C++ Program Output: Forward Difference Table

Enter number of data?
5
Enter data:
x[0] = 40
y[0] = 31
x[1] = 50
y[1] = 73
x[2] = 60
y[2] = 124
x[3] = 70
y[3] = 159
x[4] = 80
y[4] = 190

FORWARD DIFFERENCE TABLE
40      31      42      9       -25     37
50      73      51      -16     12
60      124     35      -4
70      159     31
80      190