#include <signal.h>
int quit=0;
void handler(int signal){ quit=1;}
void compare() {
    signal(SIGINT,handler);
    TCanvas c;
    c.SetLogz();
    TFile f18("../../results_run18.root");
    TFile f19("../../results_run19.root");
    TFile f20("../../results_run20.root");
    TFile f21("../../results_run21.root");
    TH2F *h18 = (TH2F*)(f18.Get("pcz_vs_sx3z"));
    TH2F *h19 = (TH2F*)(f19.Get("pcz_vs_sx3z"));
    TH2F *h20 = (TH2F*)(f20.Get("pcz_vs_sx3z"));
    TH2F *h21 = (TH2F*)(f21.Get("pcz_vs_sx3z"));

    h18->GetYaxis()->SetRangeUser(-200,200);
    h19->GetYaxis()->SetRangeUser(-200,200);
    h20->GetYaxis()->SetRangeUser(-200,200);
    h21->GetYaxis()->SetRangeUser(-200,200);
    h18->GetXaxis()->SetRangeUser(0,100);
    h19->GetXaxis()->SetRangeUser(0,100);
    h20->GetXaxis()->SetRangeUser(0,100);
    h21->GetXaxis()->SetRangeUser(0,100);

    while(!quit) {
        h18->Draw("COLZ");
        gPad->Modified(); gPad->Update(); while(gPad->WaitPrimitive());
        h19->Draw("COLZ");
        gPad->Modified(); gPad->Update(); while(gPad->WaitPrimitive());
        h20->Draw("COLZ");
        gPad->Modified(); gPad->Update(); while(gPad->WaitPrimitive());
        h21->Draw("COLZ");
        gPad->Modified(); gPad->Update(); while(gPad->WaitPrimitive());
    }

    f18.Close();
    f19.Close();
    f20.Close();
    f21.Close();
}