How do I put X and Y axis labels on a TGraph?  I tried
  gr->GetXaxis()->SetLabel("dE/dx cut");
  gr->Draw("AC");
but no axis label appeared.
Also, when I plot a new graph to a prexisting canvas, the
axes numbers come out all garbled.  If I do a c1->Clear()
first, then the TGraph plots fine.
Thanks.
Stephen