codigo que calcule y grafique una regresion lineal

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>

#include "gnuplot-iostream.h"

using namespace std;

double ajuste_lineal(vector<double> x, vector<double> y, int n) {
  double a, b;
  
  double media_x = 0;
  double media_y = 0;
  double sum_xy = 0;
  double sum_x2 = 0;
  
  for (int i = 0; i < n; i++) {
    media_x += x[i];
    media_y += y[i];
    sum_xy += (x[i] * y[i]);
    sum_x2 += (x[i] * x[i]);
  }
  
  a = (n * sum_xy - media_x * media_y) / (n * sum_x2 - media_x * media_x);
  b = (media_y - a * media_x) / n