Appending RDataFrame instances

[Javier_Galan]

Let’s say I have 3 instances of RDataFrame, i.e. d1, d2 and d3. All of them with the same columns structure.

I need to work with them separately and then later I want to merge them in the most efficient way, without having to Snapshot it to disk previously.

I have seen the following post: Appending RDataFrame - #2 by etejedor you recommend doing something like

RDataFrame("t", {"f1.root", "f2.root", "f3.root"})

However, would not be possible to do directly something like this?

RDataFrame("mergedDF", {d1,d2,d3})

[eguiraud]

Hello @Javier_Galan ,

appending RDF objects directly is not possible unfortunately.

Cheers,
Enrico

[Javier_Galan]

Oh, that’s a pity, it is like there is no TChain equivalent on RDataFrame.