// Draw a Bidimensional Histogram in many ways
// together with its profiles and projections

void macro7(){
   gStyle->SetPalette(kBird);
   gStyle->SetOptStat(0);
   gStyle->SetOptTitle(0);

   auto bidi_h = new TH2F("bidi_h","2D Histo;Gaussian Vals;Exp. Vals",
                          30,-5,5,  // X axis
                          30,0,10); // Y axis

   TRandom3 rgen;
   for (int i=0;i<500000;i++) {
      bidi_h->Fill(rgen.Gaus(0,2),10-rgen.Exp(4),.1);
   }

   auto c=new TCanvas("Canvas","Canvas",800,800);
   c->Divide(2,2);
   c->cd(1); bidi_h->Draw("Cont1");
   c->cd(2); bidi_h->Draw("Colz");
   c->cd(3); bidi_h->Draw("Lego2");
   c->cd(4); bidi_h->Draw("Surf3");

   // Profiles and Projections
   auto c2=new TCanvas("Canvas2","Canvas2",800,800);
   c2->Divide(2,2);
   c2->cd(1); bidi_h->ProjectionX()->Draw();
   c2->cd(2); bidi_h->ProjectionY()->Draw();
   c2->cd(3); bidi_h->ProfileX()->Draw();
   c2->cd(4); bidi_h->ProfileY()->Draw();
}