#include <cstdlib>
#include <cstdio>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <sstream>
#include <cmath>
#include "TColor.h"
#include "TStyle.h"
#include <TFile.h>
#include <TCanvas.h>
#include <TH2F.h>
#include <TH2D.h>
#include <TH3D.h>
#include <TSystem.h>
#include "TPaletteAxis.h"
#include <TRandom3.h>
#include <TF1.h>
#include <TF2.h>
#include <TMinuit.h>
#include "TMatrixD.h"
#include "TMatrixDSym.h"
#include "TFitter.h"
#include "TVirtualFitter.h"
#include "TRegexp.h"
#include "TCanvas.h"
#include "TMath.h"
#include "TROOT.h"
#include "TLegend.h"
#include "Math/Minimizer.h"
#include "TMinuit.h"
using namespace std;




Double_t Gaus2D(Double_t *x, Double_t *par)
{
if(par[2] > 0 && par[4] > 0)
   {
  double rx=0.;
  double ry=0.;
  double rz=0.;
  double den=0;
  rx=(x[0]-par[1])/par[2];
  ry=(x[1]-par[3])/par[4];
  rz=2.*par[5]*rx*ry;
  den= 1.-par[5]*par[5];
  double fitval = par[0]/ (2 * TMath::Pi() * par[2] * par[4] * sqrt(den))*exp(-(rx*rx+ry*ry-rz)/(2.*den));

  return fitval;
   }
else 
  return 0;
}


void fit(){


   TFile *f_image = new TFile("results_from_9072_to_9078.root","read");   
   char histoname[256];  
   
   for(int j=2;j<3;j++)   
      { 
      TH2D *h_image = (TH2D*)f_image->Get("h_det5"); 
       //sprintf(histoname,TString::Format("h_det%d",j));  
       //TH2D *h_image = (TH2D*)f_image->Get(histoname); 
          //============================== FIT WITH A 2D GAUSSIAN =================
       printf("\n");
       printf("\n");
       printf ("\033[34;01m Fitting h_det5\033[00m\n");
       //       printf ("\033[34;01m Fitting %s\033[00m\n", histoname);
       printf("\n");
       printf("\n");
       //g2D->Clear();
       TF2 *g2D=new TF2("g2D",Gaus2D,h_image->GetMean(1)-2.,h_image->GetMean(1)+2.,h_image->GetMean(2)-2.,h_image->GetMean(2)+2.,6);
       g2D->SetParNames("Const","X_{0}","#sigma_{x}","Y_{0}","#sigma_{y}","#rho");
       g2D->SetNpy(1000); 
       g2D->SetParameters(300, 0, 0.8,0,0.8,0);
       for (int i=0;i<6;i++) cout << g2D->GetParameter(i)<< endl;

       h_image->Fit(g2D,"R0LL");//,"RLL0");

       g2D->SetLineColor(2);
       delete h_image;
       g2D->Clear();
      }
     f_image->Close();      
}