Formating axis with constants

ROOT
1

Hello!
As I am now working with angles it would be nice to format the histogram axis labels

0, 0.25pi, 0.5pi, 0.75pi, pi (with nice Greek letter of course)

instead of

0, 0.785, 1.57, 2.355, 3.14

Is there a convenient way to label axes with mathematical and physical constants in Root?

Cheers,
Viesturs

2

That on our TODO list. The only way now is:

{
   Double_t pi = TMath::Pi();
   TF1*   f = new TF1("f","TMath::Cos(x/TMath::Pi())", -pi, pi);
   TH1*   h = f->GetHistogram();
   TAxis* a = h->GetXaxis();
   a->SetBit(TAxis::kLabelsHori);
   a->SetBinLabel(1,"-#pi");
   a->SetBinLabel(50,"0");
   a->SetBinLabel(100,"+#pi");
   a->SetBit(TAxis::kLabelsHori);
   a->SetLabelSize(0.075);
   f->Draw();
   gPad->Update();

   TGaxis* ax = new TGaxis(-pi, gPad->GetUymin(),
                            pi, gPad->GetUymin(),
                           -pi, pi, 510, "");
   ax->SetLabelSize(0.);
   ax->Draw();
}
3

See the new feature:
root.cern.ch/doc/master/classTGaxis.html#GA10a