#include "TGraphErrors.h"
#include "TCanvas.h"
#include "TH1D.h"
#include <iostream>                                                                                             
#include <fstream>



void Fit_Conf()
{

 const Int_t n = 10; 
  Double_t x[n] ={0};
  Double_t y[n]={0.0};
  Double_t ex[n]={0.0};
  Double_t ey[n]={0.0};
  
  
  
ifstream in("Both344and244.txt"); 

if(!in) {
  cout << "Cannot open input file!!!" << endl;
}
if(in){
    
  for(int i = 0; i<n ; i++){
    
    in >> x[i] >> y[i]  >> ey[i];
  }
  in.close();
}
  
  for(int i = 0; i<n ; i++){
    
    cout << x[i] << "," << " " << y[i] << "," << " " << ey[i] << endl;
  }


{
  TGraphErrors *p = new TGraphErrors("Both344and244.txt", "%lg %lg %lg"); 
 //  TGraphErrors *p1 = new TGraphErrors("PRD_1ps.dat", "%lg %lg %lg");
  TF1 *fit = new TF1("fit", "[0]/sqrt([1]+x) + [2]*x + [3]", 0., 1600.);
  fit->SetLineColor(kRed);
  fit->SetParameters(0.5, 1.0, 7.0, 7.0);

  p->Fit(fit, "");
  p->SetName("Stopbranch");
  p->SetTitle("Startbranch"); 
  p->Draw();

//Confidence Onterval
 const double xx[n] = {1., 2., 3., 4., 5., 6., 7., 8., 9, 10.,};
  double ci[n] = {0., 0., 0., 0.,0., 0., 0., 0.,};

    (TVirtualFitter::GetFitter())->GetConfidenceIntervals(n, 1,&xx[0], &ci[0], 0.68);
}

}