I have a question about using TTree::Draw. I’d like to create a 2d plot of a variable held in a tree but with different conditions on the x and y axes (same variable on x and y).
I have attached a script that will produce a simple tree to help illustrate my question (will hopefully work with “> root example.cxx++”).
For example, for event 2 below, I’d like to do fEnergy(detector7) vs fEnergy(detector4) which would plot 8 vs 27.
root  tv__tree->Show(2)
THits = NULL
THits.fDetector = 2, 7, 3, 4
THits.fEnergy = 4.000000, 8.000000, 9.000000, 27.000000
I’ve not found a way to do this type of plot (unless, obviously, I change the tree structure, which I’d rather not do). Is it possible (I feel I’m missing something obvious!)? I’m running x86 Gentoo with ROOT version 4.03.02.
example.cxx (1.3 KB)