RDataFrame::Vary(...) usage documentation

Dear All,

Now for the very first time, I’m trying to see how RDataFrame::Vary could be used in an “ATLAS analysis”. I may very well not be the first one to try this, though I haven’t seen any presentations in the experiment yet on people having done this successfully yet. :thinking:

I’m embarrassed to say how long it took me to figure out exactly how I should implement some functors that could be used with RDF::Vary...). But I think by now I managed.

The reason I’m opening this thread is because I found the documentation of the support for systematic variations in RDF a bit lacking. :slightly_frowning_face: I gathered by now that this is still an experimental feature in the code, but the documentation is not even clear about that. :slightly_frowning_face: For instance it took me a moment to find that the code example in ROOT: ROOT::RDF::RInterface< Proxied, DataSource > Class Template Reference should rather look like:

auto hx = ROOT::RDF::Experimental::VariationsFor(nominal_hx);

Since even in the master branch that function is still in the Experimental namespace. :thinking:

But don’t understand my complaints too negatively. I really appreciate the work on this RDF feature. I just wonder if more discussion between ATLAS and the ROOT team could benefit this code. :thinking:


ROOT Version: 6.28/10
Platform: Linux
Compiler: GCC 13

1 Like

Hi @krasznaa, thanks a lot for your detailed report!

I invite @mczurylo to take a look and improve the documentation accordingly :slight_smile:

1 Like

Hi @krasznaa,

Thanks a lot for your insightful comment. I can clearly see your point, the documentation will be improved ASAP.

I just wonder if more discussion between ATLAS and the ROOT team could benefit this code. :thinking:

Sure, we are always open to hear what are the ATLAS needs regarding RDF. We can discuss more details offline via email/MM.

Have a nice day!


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.