I think that …
- the first “Draw” creates axes (so they do not exist prior to this call)
- there seems to exist a bug in ROOT related to “SetTitle” … a brutal fix …
… if you “Draw” your TMultiGraph first, then use:
total_graph->GetHistogram()->SetTitle(“Charge State Probability”);
… before the first “Draw”, use:
total_graph->SetTitle(“Charge State Probability”);