Write a c programme to perform newton's divided difference formula?

Answer 1

#include<stdio.h>

#include<math.h>

int main()

{

float x[10],y[10][10],sum,p,u,temp;

int i,n,j,k=0,f,m;

float fact(int);

printf("\nhow many record you will be enter: ");

scanf("%d",&n);

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

{

printf("\n\nenter the value of x%d: ",i);

scanf("%f",&x[i]);

printf("\n\nenter the value of f(x%d): ",i);

scanf("%f",&y[k][i]);

}

printf("\n\nEnter X for finding f(x): ");

scanf("%f",&p);

for(i=1;i<n;i++)

{

k=i;

for(j=0;j<n-i;j++)

{

y[i][j]=(y[i-1][j+1]-y[i-1][j])/(x[k]-x[j]);

k++;

}

}

printf("\n_____________________________________________________\n");

printf("\n x(i)\t y(i)\t y1(i) y2(i) y3(i) y4(i)");

printf("\n_____________________________________________________\n");

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

{

printf("\n %.3f",x[i]);

for(j=0;j<n-i;j++)

{

printf(" ");

printf(" %.3f",y[j][i]);

}

printf("\n");

}

i=0;

do

{

if(x[i]<p && p<x[i+1])

k=1;

else

i++;

}while(k != 1);

f=i;

sum=0;

for(i=0;i<n-1;i++)

{

k=f;

temp=1;

for(j=0;j<i;j++)

{

temp = temp * (p - x[k]);

k++;

}

sum = sum + temp*(y[i][f]);

}

printf("\n\n f(%.2f) = %f ",p,sum);

return 0;

}