int cluster2(const char * input = "Chargeff.csv", const char * output = "pixels.root"){
    ifstream fint;   //input file
    fint.open(input);
    if(!fint.is_open()){
      cout << "Input File " << input << " had issues while opening, closing the script\n";
        return -1;
    }

    TFile * fout = new TFile(output, "RECREATE");
    int pixarrX = 727, pixarrY = 727;       //number of pixels in 2D
    vector <int> posx;
    vector <int> posy;
    vector <float> thick;
    vector <double> dose;
    vector <int> eventID;
    string spx, spy, sth, sd, spn;
    string line;
    stringstream ssth, ssd;
    double d = 0, t = 0;
    while (getline(fint,line)){
        if(line.length() == 1 || line.empty()){
            continue;
        }
        else if(isdigit(line.at(0))){
            stringstream s_data(line);

            getline(s_data,spx,',');
            getline(s_data,spy,',');
            getline(s_data,sth,',');
            getline(s_data,sd,',');
            getline(s_data,spn,',');

            stringstream ssth(sth), ssd(sd); 

            ssth >> t;      //common procedure for the conversion
            ssd >> d;
	  
            posx.push_back(stoi(spx));  //for int (not in scientific notation) the stoi function is used
            posy.push_back(stoi(spy));
            thick.push_back(t);
            dose.push_back(d);
       	    eventID.push_back(stoi(spn));
    }
    
    TH1F *h_cluster_size = new TH1F("cluster_size","cluster_size",100, 0.,6.);
    int cluster_size = 0;
    for(int i = 0; i < eventID; i++){ //looping over number of events

    cluster_size  = posx.size();
     
    }
    h_cluster_size->Fill(cluster_size);
    h_cluster_size->Write();
    fout->Close();
    return 0;
    }
}