Draw multiple root files along with graph file on the same canvas

[Dilicus]

Hi,
since in your first.root file have no canvas you have to get the histogram.

TFile *f1 = TFile::Open(“first.root”);
TH1D *h2 = (TH1D)f1->Get(“h2”);
h2->SetName("F");
h2->Draw(“hist same”);
h2->SetLineColor(1);
h2->SetLineWidth(2);

almost the same problem is addressed here

Draw two histograms in same canvas from two different root files

Hi, I attached below a modified version of your code. (Remember to put you code between two ``` in this way will appear highlited). there are 3 main point I added two ; after the opening of the files. When you use Get() to get the histogram recast as a TH1D and not a TCanvas, otherwise you cannot the TH1D methods. the Draw is made using the TH1D pointer and not the name of the histogram in the file. void macro() { TFile *f1 = TFile::Open("first.root"); TH1D *h1= (TH1D*)f1…

Ciao,
Stefano