{
   TGraph2D *dt2 = new TGraph2D();
   TRandom2 rg;
   for(int i =0; i < 500; i++){
             double phi = rg.Uniform(0,2*TMath::Pi());
             double theta = rg.Uniform(0,TMath::Pi());
             double point = cos(phi)*cos(phi);
             dt2->SetPoint(i,phi,theta,point);
   }
   TCanvas* c1 = new TCanvas("glc1","c1",640,480);
   TAxis3D rulers; 
   dt2->Draw("glsurf1sph");
   rulers->Draw("");
}