Draw two histograms in same canvas from two different root files

Newbie
3

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->Get("h1");
    h1->Draw("hist l");
    h1->SetLineWidth(3);
    h1->SetLineColor(2);
    
    TFile *f2 = TFile::Open("second.root");
    TH1D *h2 = (TH1D*)f2->Get("h1");
    h2->SetLineWidth(2);
    h2->SetLineColor(4);
    h2->Draw("hist l same");
    
}