{ x[NR] = $1 y[NR] = $2 } END{ if(NR <= 1) exit for(i in x){ sum_x += x[i] sum_y += y[i] sum_x2 += x[i] ^ 2 sum_xy += x[i] * y[i] } if(NR * sum_x2 - sum_x ^ 2 == 0.0) exit a = (NR * sum_xy - sum_x * sum_y) / (NR * sum_x2 - sum_x ^ 2) b = (sum_x2 * sum_y - sum_x * sum_xy) / (NR * sum_x2 - sum_x ^ 2) for(i in x){ sum_e2 += (a * x[i] + b - y[i]) ^ 2 } print a, b, sqrt(sum_e2 / NR) }