Pi and so on on histogram axis

ROOT
1

How do I have my histogram axis contain values expressed as pi/2, pi and so on, instead of Arabic numbers?

2

That is not something provided right now (it is on our ToDo list). The only way to do it for the time being is to use alphanumeric axis as chown in the following example:

{
   TCanvas *c1 = new TCanvas("c1","Test",0,0,700,700);
   TFile *example = new TFile("hsimple.root");
   hpx->Draw();
   hpx->GetXaxis()->SetBit(TAxis::kLabelsHori);
   hpx->GetXaxis()->SetBinLabel(10,"-#pi");
   hpx->GetXaxis()->SetBinLabel(50,"0");
   hpx->GetXaxis()->SetBinLabel(90,"+#pi");
}

The file hsimple.root is produced by $ROOTSYS/tutorials/hsimple.C

3

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