TTree::Project within pyROOT

ROOT
,
1

I am trying to use TTree::Project within pyROOT, and am having some issues.

My code is as follows:

import ROOT

numBins = 350
minE = 0.0
maxE = 3500.0

# Define the histograms
possible_bjets = ROOT.TH1D("possible_bjets", "Possible b-jets;Jet Energy (GeV);Number of jets", numBins, minE, maxE)
tagged_bjets = ROOT.TH1D("tagged_bjets", "Tagged b-jets;Jet Energy (GeV);Number of jets", numBins, minE, maxE)

possible_mistags = ROOT.TH1D("possible_mistags", "Possible Mistags;Jet Energy (GeV);Number of jets", numBins, minE, maxE)
mistagged_jets = ROOT.TH1D("mistagged_jets", "Mistagged Jets;Jet Energy (GeV);Number of jets", numBins, minE, maxE)

# Define the cuts
etaCut = ROOT.TCut("abs(jeteta) < 2.3")
decayCut = ROOT.TCut("BdecTrans > 25.7 && BdecTrans < 122.5")
bCut = ROOT.TCut("(abs(Bid) < 600 && abs(Bid) > 500) || (abs(Bid) < 6000 && abs(Bid) > 5000)")
notB = ROOT.TCut("!(%s)" % bCut)
hitCut = ROOT.TCut("max( (jethit2_cone1 - jethit1_cone1) / jethit1_cone1," \
                       " max( (jethit3_cone1 - jethit2_cone1) / jethit2_cone1," \
                       " (jethit4_cone1 - jethit3_cone1) / jethit3_cone1 ) ) >= 1");

evaluationFile = ROOT.TFile.Open("deep-learning-evaluation.root")

print "Number of possible b-jets: " + str(evaluationFile.Jets.GetEntries(str(etaCut + decayCut + bCut)))
print "Number of possible light-jets: " + str(evaluationFile.Jets.GetEntries(str(etaCut + notB)))

evaluationFile.Jets.Project("possible_bjets", "jetEnergy", str(etaCut + decayCut + bCut))
evaluationFile.Jets.Project("possible_mistags", "jetEnergy", str(etaCut + notB))

evaluationFile.Jets.Project("tagged_bjets", "jetEnergy", str(etaCut + decayCut + bCut + hitCut))
evaluationFile.Jets.Project("mistagged_jets", "jetEnergy", str(etaCut + notB + hitCut))

print "Number of entries for possible_bjets: " + str(possible_bjets.GetEffectiveEntries())
print "Number of entries for tagged_bjets: " + str(tagged_bjets.GetEffectiveEntries())
print "Number of entries for possible_mistags: " + str(possible_mistags.GetEffectiveEntries())
print "Number of entries for mistagged_jets: " + str(mistagged_jets.GetEffectiveEntries())

taggingEfficiency = ROOT.TEfficiency(tagged_bjets, possible_bjets)
mistaggingRate = ROOT.TEfficiency(mistagged_jets, possible_mistags)

canvas = ROOT.TCanvas("canvas", "Efficiency/Mistagging Canvas")
taggingEfficiency.SetLineColor(2)
taggingEfficiency.Draw("e1p")

mistaggingRate.SetLineColor(3)
mistaggingRate.Draw("SAME")

legend = ROOT.TLegend(0.7, 0.7, 0.9, 0.9)
legend.AddEntry(taggingEfficiency, "Efficiency of tagging #b-jets")
legend.AddEntry(mistaggingRate, "Mistagging Rate")
legend.Draw()

canvas.Show()

raw_input("Press enter to exit...")

However, my output goes something like:

Number of possible b-jets: 14223
Number of possible light-jets: 949104
Number of entries for possible_bjets: 0.0
Number of entries for tagged_bjets: 0.0
Number of entries for possible_mistags: 0.0
Number of entries for mistagged_jets: 0.0
Press enter to exit…

Which suggests to me that I am doing something wrong within TTree::Project, however, I am using it how I would use it within CINT or ACLiC and so I am not sure why it is misbehaving!

2

I am now not so sure that the issue is with TTree::Project, as whilst the number of entries was listed as zero, when filling the TH1Ds manually the graph still did not display.

Does anyone have any ideas? Maybe @couet @Danilo?

3

Does it work if you use it in CINT/Cling or AClic ?

4

(I have now double checked), it appears it doesn’t work in CINT or ACLiC either… Any ideas?

5

The issue is that Project does not find the histogram in the ROOT current directory.
Try something like

gROOT.cd() # make sure they are in gROOT
possible_bjets = ROOT.TH1D("possible_bjets", "Possible b-jets;Jet Energy (GeV);Number of jets", numBins, minE, maxE)
...
evaluationFile = ROOT.TFile.Open("deep-learning-evaluation.root") # This change the current directory
gROOT.cd() # make sure the histo's directory is the current directory.
...
evaluationFile.Jets.Project("possible_bjets", "jetEnergy", str(etaCut + decayCut + bCut))

Cheers,
Philippe.

6

Thanks, that fixed my issue! However, the efficiency graph still is not drawn; but no errors are presented?

7

This blocks ROOT from actual refreshing/displaying.

Cheers,
Philippe.

8

Without it though, the canvas opens and closes instantly?

9

You need to find a way to ‘peg’ the python reference to the canvas to avoid its deletion.

10

I am unsure how to do this (I’m unfamilar with python). My understanding was that the garbage collector would do this automatically without giving me a choice? I can run gc.disable at the beginning of my script, but I don’t think this will help?

11

yes python automatically exit when you do:

$ python graph.py

graph.py is one of the example in $ROOTSYS/tutorials/pyroot

to behave like ROOT interactive with a prompt. You can do:

$ python
Python 2.7.10 (v2.7.10:15c95b7d81dc, May 23 2015, 09:33:12)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import ROOT
>>> execfile("graph.py")
 i 0 0.000000 1.986693
 i 1 0.100000 2.955202
 i 2 0.200000 3.894183
 i 3 0.300000 4.794255
 i 4 0.400000 5.646425
 i 5 0.500000 6.442177
 i 6 0.600000 7.173561
 i 7 0.700000 7.833269
 i 8 0.800000 8.414710
 i 9 0.900000 8.912074
 i 10 1.000000 9.320391
 i 11 1.100000 9.635582
 i 12 1.200000 9.854497
 i 13 1.300000 9.974950
 i 14 1.400000 9.995736
 i 15 1.500000 9.916648
 i 16 1.600000 9.738476
 i 17 1.700000 9.463001
 i 18 1.800000 9.092974
 i 19 1.900000 8.632094
>>>

The TCanvas stays open .

12

It does, but still no graph has been drawn! :frowning:

13

can you try:

taggingEfficiency.SetLineColor(2)
taggingEfficiency.Draw("Ae1p")

mistaggingRate.SetLineColor(3)
mistaggingRate.Draw("L")
14

I still get a blank graph; the Legend is displayed, but no graph.

15

Are the axis displayed ?
Do you get some error message ?

Also try:

taggingEfficiency.SetMarkerColor(2);
taggingEfficiency.SetMarkerStyle(20);
16

No, the axes are not displayed either, but I get no error message!

17

Have you try the marker attributes changes I suggested ?

18

Yes, I used those and it didn’t make a difference!

Thanks for your persistence and help so far!

19

To help you further I would need a script I can run. The one you posted refers to some ROOT file I do not have.

20

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.