#include "linearFit.C"

#define N 10

int fit_errors()
{
  
  double x[N], y[N];
  double errx[N], erry[N];
  double par[2];
  fstream f, g, h;
  
  f.open("xval.dat",ios::in);
  g.open("yval.dat",ios::in);
  h.open("erry.dat",ios::in);
  
  for (int i = 0; i < N; i++) {
    f >> x[i];
    g >> y[i];
    errx[i] = 0.;
    h >> erry[i];
  }
  
  TGraphErrors *retta_err = new TGraphErrors(N,x,y,errx,erry);
  TCanvas *c2 = new TCanvas("c2","Fit Lineare (pol1)",600,400);
  retta_err->Draw("A*");
  retta_err->Fit("pol1");
  
  // Oppure con funzione definita dall'utente
  
  TF1 *f1 = new TF1("f1","[0]+[1]*x",0.,10.);
  TCanvas *c3 = new TCanvas("c3","Fit Lineare",600,400);
  retta_err->Draw("A*");
  retta_err->Fit("f1");
  
  return 0;

}