So I have a root file with the path Users/andrewbarajas/output_IdId_Mc16a.root and with in this root file I have a TH1D histogram and I need to be able ti draw out a histogram from that root file. The histogram is TH1D wElEta
I tried this but got an error
TFile *f = new TFile("/Users/andrewbarajas/output_IdId_Mc16a.root"); root  TH1D *h = (TH1D*)f->Get("wElEta"); root  h->Draw();
Error in : Trying to dereference null pointer or trying to call routine taking non-null arguments.
Execution of your code was aborted.
ROOT_prompt_2:1:1: warning: null passed to a callee that requires a non-null argument [-Wnonnull]