#include "TFile.h"
#include "TTree.h"
#include "TString.h"
#include <assert.h>
#include <iostream>
#include <sstream>
#include "TCanvas.h"
#include "TStyle.h"
#include "TH1D.h"

void clustering(){
  
  gStyle->SetOptFit();

  TString files[7]={"data/pion.15deg.reco.root",
		    "data/pion.20deg.reco.root",
		    "data/pion.30deg.reco.root",
		    "data/pion.40deg.reco.root",
		    "data/pion.50deg.reco.root",
		    "data/pion.60deg.reco.root",
		    "data/pion.70deg.reco.root"};
  
  TCanvas* c=new TCanvas("Clusters","Clusters",10,10,500,900);
  c->Divide(3,7);

  int count=0;

  for(int i=0; i<7; ++i){
    TFile* file=new TFile(files[i],"READ");
    TTree* tr=(TTree*)file->Get("cbmsim");
    assert(tr!=0);

    c->cd(++count);
    std::ostringstream histo;
    histo  <<"hRX"<<count;
    std::ostringstream select;
    select << "TrackFitStat._TpcResX>>"<<histo.str()<<"(100,-1,1)";
    tr->Draw(select.str().c_str(),"abs(TrackFitStat._TpcResX)<1");
    TH1F* hX = (TH1F*)gDirectory->Get(histo.str().c_str());
    hX->Fit("gaus");
    
    c->cd(++count);
    std::ostringstream histo2;
    std::ostringstream select2;
    histo2  <<"hRY"<<count;
    select2 << "TrackFitStat._TpcResY>>"<<histo2.str()<<"(100,-1,1)";
    tr->Draw(select2.str().c_str(),"abs(TrackFitStat._TpcResY)<1");
    TH1F* hY = (TH1F*)gDirectory->Get(histo2.str().c_str());
    hY->Fit("gaus");


    c->cd(++count);
    tr->Draw("TpcCluster._size","");

  }// end loop over files


}