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 surface on the same plot",20,1,3,20,1,3);
   frame->SetMaximum(1.2);

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

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

   frame->Draw("lego0");
   TExec *ex1 = new TExec("ex1","gStyle->SetPalette(55, 0, 0.5);");
   ex1->Draw();
   f1->Draw("surf2 same fb bb");

   TExec *ex2 = new TExec("ex2","gStyle->SetPalette(75, 0, 0.5);");
   ex2->Draw();
   f2->Draw("surf2 same fb bb");
}