# earth¶

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

Author: Olivier Couet (from an original macro sent by Ernst-Jan Buis)
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, November 29, 2022 at 11:16 AM.

In [1]:
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;


Draw all canvases

In [2]:
gROOT->GetListOfCanvases()->Draw()