void test(){


  TFile* file = new TFile("file.root","READ");

  TH3F* hist = (TH3F*) file->Get("hist");
  hist->SetName("hist");
  hist->SetTitle("hist");

  gStyle->SetCanvasPreferGL(kTRUE);
  gStyle->SetPalette(1);

  hist->Draw("glcolz");



}