regression.c

#include <stdio.h>
#define S 50
int main()
{
int n, i;
float x[S], y[S], sumX = 0, sumX2 = 0, sumY = 0, sumXY = 0, a, b;
/* Input */
printf("Number Of Data Points\n");
scanf("%d", &n);
printf("Enter data for x:\n");
for (i = 1; i <= n; i++)
{
scanf("%f", &x[i]);
}
printf("Enter data for y:\n");
for (i = 1; i <= n; i++)
{
scanf("%f", &y[i]);
}
/* Calculating Required Sum */
for (i = 1; i <= n; i++)
{
sumX = sumX + x[i];
sumX2 = sumX2 + x[i] * x[i];
sumY = sumY + y[i];
sumXY = sumXY + x[i] * y[i];
}
/* Calculating a and b */
b = (n * sumXY - sumX * sumY) / (n * sumX2 - sumX * sumX);
a = (sumY - b * sumX) / n;
/* Displaying value of a and b */
printf("Values are: a=%0.2f and b= %0.2f", a, b);
printf("\nEquation of best fit is: y = %0.2f+ %0.2fx\n", a, b);
return (0);
}