# Numerical Methods:Fitting the curve of the form y = a + bx using least square method in C

**Source Code : **

///Curve fitting of a straight line of the form y = a + bx #include<stdio.h> #include<math.h> int main(){ int ax[20], ay[20], i, n; int sum_x = 0, sum_xy = 0, sum_x2 = 0, sum_y = 0 ; float a , b; printf("Enter no of records: "); scanf("%d", &n); printf("Enter Data: "); printf("\nX Y\n"); for(i = 0; i < n; i++){ scanf("%d%d", &ax[i], &ay[i]); } for(i = 0; i < n; i++){ sum_x += ax[i]; sum_y += ay[i]; sum_xy += ax[i] * ay[i]; sum_x2 += pow(ax[i], 2); } b = (n*sum_xy - sum_x*sum_y)/(n*sum_x2 - pow(sum_x,2)); a = (sum_y - b*sum_x)/n; printf("\na = %.3f b = %.3f", a, b); printf("\nThe Equation is %.3f + %.3fX\n\n", a, b); return 0; }