About the variables in muons.root

ROOT chat

Hi Edgar,

I am confused by the structure of the tree. Is it that each instance has an array of pt or that each instance has 1 value for mu_pt?
If it is an array, why would it be? Is it because pt is changing with time? But then, what does its histogram represent? is it representing what is the highest pt of the muon had?
If it is a single value, what is the point of drawing a histogram? (from the formula of inv_m, I will only get a single value)

Also, what is runno (the run number) in the muons.root?

Thanks, Elim =D

Problems with muons.root and macros file

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Hi,

I have difficulty opening the muons.root file and the macros file. For the macros file: if I use wget in the linux terminal it says “authorization failed”. If I try to copy the code into an emacs file and then move it to the root/macros directory so that I can access it in root, it does not work either. It says permission denied.
In addition, I can only open muons.root by clicking on it, which brings up root with the file in it. This is fine, but I need to be able to access the macros file or any .C file I create too. Can anyone help?

Thanks,
Chelsea

Problems with lxplus?

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Hello,
So I am having problems opening ROOT in lxplus. If I just call ROOT by typing “root” it says that the command isn’t found even though I am in the right directory and I have ROOT in there. I have tried typing “./root &” since that is how I open ispy in lxplus but that says Permission Denied. I have tried “chmod +x root” but it doesn’t change anything. Do you know what I am doing wrong? I am probably making a simple mistake since I don’t know many linux commands.

Andrea

Hard Muons

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Hi Edgar,
I was working on trying to figure out which muons are the hardest muons. Are the hardest muons the ones with the most energy? I scanned “mu_e”, but I can’t tell which muons have the highest energy because it seems scattered throughout the events.. I’m not sure if what I said makes sense.. I also thought that if I drew “mu_e” it would help me figure out which muons had the highest energy, but it plots the number of muons that had a particular energy, not which muon had what energy..right?
I’m aware that there is a GetMaximum function in TTree, but it won’t tell us which event produced the maximum energy..so will that help us?

Thank you,
Ashley

About AnalyzeRootuple.C

ROOT chat

Hi Edgar,

I am studying the program AnalyzeRootuple.C, and I remember that we were playing with the code during class. One thing that you did is to plot a histogram for mu_charge, and you declared the float variable mu_charge by the statement: float mu_charge[200]. But I don’t understand why it’s 200…

And what happens when the statement “mytree->AddBranchAddress(“mu_charge”,μ_charge)” is executed? I originally thought that it is to turn the pointer to the branch called “mu_charge” existed in mytree. But when I check the Function Members in TTree, it says the function AddBranchAddress() returns an integer. What does that integer means? Is it a temperary label for the computer to point to where mu_charge is stored?

Thanks, Elim =)