I have a TTree with several array branches, and I’d like to make aliases out of them.
Say I have two array branches px and py, I define a pT alias as:
This new variable works fine if I want to sum over it. This is
give identical results. But it doesn’t work if I want to access individual values:
The former gives the error message
How should I define the alias so it is equivalent to “(px^2+py^2)” instead?