TGraph doesn't set correct range while drawing

ROOT
1

Hi,

I’m creating some TGraph objects in athena, and registering them using the regGraph method of THistSvc. They transfer fine, except they seem ignorant of their own boundaries. If I open the root file athena outputs with CINT, and tell them to draw, it doesn’t correctly scale the x-axis, so none of the data points show. I can only draw it if I use something else to set the borders. For example, putting the TGraph into a TMultiGraph, and then drawing the TMultiGraph works.

However, it doesn’t seem like this should necessary. Any help would be appreciated. Thank you.

2

Are you drawing your graph with option “a” ? such that the graph range is computed.

Rene

3

Yes. For example, where my graph is called calGraph, I type:

calGraph->Draw(“AP”)
It only draws the x and y axes up to about 1. However, the following does draw the points correctly:

TMultiGraph mg
mg.Add(calGraph)
mg.Draw(“AP”)

It also works to draw something else, like say a TH1F, and then draw the TGraph on the same TCanvas.

4

Could you post the shortest running script reproducing your problem?
Also specify which version of ROOT.

Rene