Dear all

I tried to use MakeClass for some data analysis but I had some problem with the vectors lorentz which can’t be generated automatically so I m trying to do it in pyroot that I used only when I was summer student, so I am not very comfortable with.

For instance here is my little pyroot script:

```
#!/usr/bin/python
import ROOT
from math import *
from ROOT import*
from glob import glob
from ROOT import gROOT, TCanvas, TF2
gROOT.Reset()
f=ROOT.TFile("run8TeV.0.txt.root")
f1 = ROOT.TFile("myclass.root", "recreate")
#c1 = TCanvas( 'c1', 'Example with Formula', 200, 10, 700, 500 )
h = TProfile("eOpinHisto","eOpin vs eta 1RG",60,-0.441,0.,0.,1.2)
#h = TH1D("eOpinHisto","eOpin vs eta 1RG",60,0,1.2)
for e in f.redTree:
# h.Fill(e.electron0_p4.eta())
A =e.electron0_p4.e()/sqrt(pow(e.electron0_p4In.px(),2)+pow(e.electron0_p4In.py(),2)+pow(e.electron0_p4In.pz(),2))
B =e.electron0_p4.eta()
h.Fill(A,B)
# print e.electron0_p4.eta()
h.Draw()
h.Write()
f1.Close()
#c1.Update()
```

With this script I get the plot pyroot.pdf I attached where I expected the root.pdf attached obtained by doing:

`redTree->Draw("(electron0_p4.e()/sqrt(pow(electron0_p4In.px(),2)+pow(electron0_p4In.py(),2)+pow(electron0_p4In.pz(),2))):electron0_p4.eta()>>h(60,-0.441,0.441,0,1.2)","","prof")`

So I would really appreciate if someone could tell me why I get this numbers of entries reduced please, it seems that the negatif part of the plot obtained with the pyroot script is empty and I don’t know why.

Thanks in advance.

Cheers

pyroot.pdf (13.9 KB)

root.pdf (16.3 KB)