earth.C File Reference

Detailed Description

This tutorial illustrates the special contour options.

• "AITOFF" : Draw a contour via an AITOFF projection
• "MERCATOR" : Draw a contour via an Mercator projection
• "SINUSOIDAL" : Draw a contour via an Sinusoidal projection
• "PARABOLIC" : Draw a contour via an Parabolic projection

 
TCanvas *earth(){
 
   gStyle->SetOptTitle(1);
   gStyle->SetOptStat(0);
 
   TCanvas *c1 = new TCanvas("c1","earth_projections",700,700);
   c1->Divide(2,2);
 
   TH2F *ha = new TH2F("ha","Aitoff",    180, -180, 180, 179, -89.5, 89.5);
   TH2F *hm = new TH2F("hm","Mercator",  180, -180, 180, 161, -80.5, 80.5);
   TH2F *hs = new TH2F("hs","Sinusoidal",180, -180, 180, 181, -90.5, 90.5);
   TH2F *hp = new TH2F("hp","Parabolic", 180, -180, 180, 181, -90.5, 90.5);
 
   TString dat = gROOT->GetTutorialDir();
   dat.Append("/graphics/earth.dat");
   dat.ReplaceAll("/./","/");
 
   ifstream in;
   in.open(dat.Data());
   Float_t x,y;
   while (1) {
     in >> x >> y;
     if (!in.good()) break;
     ha->Fill(x,y, 1);
     hm->Fill(x,y, 1);
     hs->Fill(x,y, 1);
     hp->Fill(x,y, 1);
   }
   in.close();
 
   c1->cd(1); ha->Draw("aitoff");
   c1->cd(2); hm->Draw("mercator");
   c1->cd(3); hs->Draw("sinusoidal");
   c1->cd(4); hp->Draw("parabolic");
 
   return c1;
}

Author

Olivier Couet (from an original macro sent by Ernst-Jan Buis)

Definition in file earth.C.