List of Entries Obeying a Certain Condition from TTree

[alexwenym]

How to access the value of branch variables?

Hello, I’m a beginner.I create a file pixels.root and a tree with a pixel branch and totE branch. In my programming, I use a loop ( for (int i=0; i< 36; i++) {pixel =i)};I obtain a histogram corresponding to pixels. My problem: I would like to retrieve the tenth pixel with its energy associated (and so forth) and to create a energy histogram per pixel. Or simply how to access the value of branch variables? TFile *myfile= new TFile(“pixels.root”,“READ”); Ttree tree= (Ttree myfile)->Get(“tre…

See this post. The first answer pretty much does exactly what you want - you can impose your own conditions on certain variables and do other things with other variables in the same event.