void multi5() {
   gStyle->SetOptStat(0);

   gStyle->SetCanvasPreferGL(kTRUE);
   TCanvas *c  = new TCanvas("c","c",0,0,1000,800);

   TH2F *frame = new TH2F ("frame","Example of two surfaces on the same plot",1,1,4,1,1,4);

   TF2  *f1 = new TF2("f1","0.1+(1-(x-2)*(x-2))*(1-(y-2)*(y-2))",1,4,1,4);
   TF2  *f2 = new TF2("f2","0.1+(2-(x-3)*(x-3))*(2-(y-3)*(y-3))",1,4,1,4);
   TH2F *h1 = (TH2F*)f1->GetHistogram();
   TH2F *h2 = (TH2F*)f2->GetHistogram();

   double max = TMath::Max(h1->GetMaximum(),h2->GetMaximum());
   h1->SetMaximum(max);
   h2->SetMaximum(max);
   frame->SetMaximum(max);

   double min = TMath::Max(h1->GetMinimum(),h2->GetMinimum());
   h1->SetMinimum(min);
   h2->SetMinimum(min);
   frame->SetMinimum(min);

   f1->SetLineWidth(1);
   f1->SetLineColor(kBlue);
   f2->SetLineWidth(1);
   f2->SetLineColor(kBlack);

   frame->Draw("lego0 fb");
   TExec *ex1 = new TExec("ex1","gStyle->SetPalette(55, 0, 0.5);");
   ex1->Draw();
   h1->Draw("surf2 same fb ");

   TExec *ex2 = new TExec("ex2","gStyle->SetPalette(52, 0, 0.5);");
   ex2->Draw();
   h2->Draw("surf2 same fb ");
}