Modification of a RDataFrame with an extracted column

Hi eguiraud,

Basically, in TTree A one row correspond to one simulated event. It’s the same in Tree B except that some events are missing and cycleNum column contains an integer that refer to a row number of TTree B

TTree A TTree B
row data row cycleNum
1 1 1
2 (don’t exist) (don’t exist)
3 2 3
4 3 4
5 (don’t exist) (don’t exist)

I will look at tree index thanks
And thanks for your quick response

greetings