{
  TFile f("trace.root");
  TNtuple *ntp;
  f.GetObject("ntp", ntp);
  TCanvas c;
  ntp->Draw("ampl:t");
  c.SaveAs("plot1.pdf");
  ntp->Draw("ampl:t", "t>2e-6");
  c.SaveAs("plot2.pdf");
  ntp->Draw("ampl:t", "t>2e-6&&abs(ampl)<0.01");
  c.SaveAs("plot3.pdf");
  ntp->Draw("ampl", "t<2e-6");
  c.SaveAs("plot4.pdf");
}