Accessing histograms from directories from a rootfile

sanjeeda · July 25, 2019, 6:37am

Hi,

I have a root file which has a directory Occupancies. Occupancies has another directory in it OccupancyL3. OccupancyL3 has 4 histograms in it. I want to access each of these histograms and normalize them. I have been referring to https://root-forum.cern.ch/t/how-to-access-directories-within-root-files/31866; but none of it seems to work in my case> I am not even able to draw a histogram. Can anyone help. Here’s a picture for clarity root

couet · July 25, 2019, 7:08am

From the browser you only need to double on the histogram to Draw it.
From the ROOT prompt just cd in the file to that directory and invoke Draw() on the histogram
you want to see.

sanjeeda · July 25, 2019, 7:15am

Ofcourse. But I am actually trying to write a macro to access the histograms and then I want to normalize them.

couet · July 25, 2019, 7:43am

use cd on the TFile you opened.