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asc:tutorials:2014october28
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asc:tutorials:2014october28 [2014/10/28 15:55] asc [Lesson 2: Using pyROOT to read xAOD] |
asc:tutorials:2014october28 [2014/10/29 13:53] asc old revision restored (2014/10/28 16:33) |
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| Line 95: | Line 95: | ||
| __Method 1. If you are at ANL, copy it__: | __Method 1. If you are at ANL, copy it__: | ||
| <code bash> | <code bash> | ||
| - | cp / | + | cp / |
| - | AOD.01482225._000140.pool.root | + | |
| </ | </ | ||
| Line 104: | Line 103: | ||
| localSetupFAX --rootVersion=current-SL6 | localSetupFAX --rootVersion=current-SL6 | ||
| voms-proxy-init -voms atlas | voms-proxy-init -voms atlas | ||
| - | xrdcp $STORAGEPREFIX/ | + | xrdcp $STORAGEPREFIX/ |
| </ | </ | ||
| Line 120: | Line 119: | ||
| setMeUpData anl-oct2014 mydata | setMeUpData anl-oct2014 mydata | ||
| </ | </ | ||
| - | The file will appear in " | + | The file will appear in " |
| Line 157: | Line 156: | ||
| - | <code python | + | <code python xAODPythonMacro.py> |
| # | # | ||
| Line 196: | Line 195: | ||
| Using this code, one can fill histograms. But the code runs slow. Below we will show how to use C++/ROOT compiled code to | Using this code, one can fill histograms. But the code runs slow. Below we will show how to use C++/ROOT compiled code to | ||
| run over this file. | run over this file. | ||
| + | |||
| + | How do you know about methods of " | ||
| + | |||
| + | <code python> | ||
| + | print dir(el.trackParticle()) | ||
| + | </ | ||
| How will you find xAOD variables without using ROOT TBrowser? Try this code: | How will you find xAOD variables without using ROOT TBrowser? Try this code: | ||
| Line 204: | Line 209: | ||
| </ | </ | ||
| - | You will see a table with the names of the variables. | ||
| - | Now you can fill a histogram in this Python code: | + | <note warning> |
| + | To run the next example, please start from a new terminal, run rcSetup. This is needed to avoid a conflict with asetup</ | ||
| - | You should create a histogram before the event loop: | + | |
| + | Now you can fill a histogram in this Python code. You should create a histogram before the event loop: | ||
| <code python> | <code python> | ||
| from ROOT import * | from ROOT import * | ||
| - | h1=TH1D(" | + | h1=TH1D(" |
| </ | </ | ||
| - | Then fill it in the event loop as h1.Fill( el.trackParticle().eta() ). | + | Then fill it in the event loop as h1.Fill( el.trackParticle().eta() ). Then we will write this histogram |
| - | + | ||
| - | Then we will write this histogram | + | |
| - | at the end (after f.Close()) | + | |
| <code python> | <code python> | ||
| Line 225: | Line 228: | ||
| hfile.Close() | hfile.Close() | ||
| </ | </ | ||
| - | ====== Lesson 3: Analysis program to read xAOD ====== | ||
| - | Now we will create a C++/ROOT analysis program and run over this input xAOD file. Do not forget to run "kinit [email protected]" | + | Here the code that write a ROOT histogram: |
| + | |||
| + | <code python xAODPythonMacro_histo.py> | ||
| + | # | ||
| + | |||
| + | import ROOT | ||
| + | ROOT.gROOT.Macro( ' | ||
| + | |||
| + | ROOT.xAOD.Init() # Initialize the xAOD infrastructure | ||
| + | |||
| + | fileName=" | ||
| + | treeName = " | ||
| + | |||
| + | f = ROOT.TFile.Open(fileName) | ||
| + | t = ROOT.xAOD.MakeTransientTree( f, treeName) # Make the " | ||
| + | |||
| + | from ROOT import * | ||
| + | h1=TH1D(" | ||
| + | |||
| + | # Print some information: | ||
| + | print( " | ||
| + | for entry in xrange( t.GetEntries() ): | ||
| + | | ||
| + | | ||
| + | | ||
| + | for el in t.ElectronCollection: | ||
| + | h1.Fill( el.trackParticle().eta() ) | ||
| + | pass # end for loop over electron collection | ||
| + | |||
| + | pass # end loop over entries | ||
| + | |||
| + | hfile=TFile(" | ||
| + | h1.Write() | ||
| + | f.Close() | ||
| + | hfile.Close() | ||
| + | </ | ||
| + | |||
| + | Now open the root file and look at the histogram. | ||
| + | ====== Lesson 3: C++/ROOT program to read xAOD ====== | ||
| + | |||
| + | Now we will create a C++/ROOT analysis program and run over this input xAOD file. | ||
| Use the same setup file as above. | Use the same setup file as above. | ||
| Line 251: | Line 293: | ||
| python Make_input < | python Make_input < | ||
| </ | </ | ||
| + | |||
| + | In case if you need xAOD data, do this: | ||
| + | |||
| + | <code bash> | ||
| + | mkdir data | ||
| + | cd data | ||
| + | localSetupFAX --rootVersion=current-SL6 | ||
| + | voms-proxy-init -voms atlas | ||
| + | xrdcp $STORAGEPREFIX/ | ||
| + | xrdcp $STORAGEPREFIX/ | ||
| + | xrdcp $STORAGEPREFIX/ | ||
| + | </ | ||
| + | |||
| + | and run: | ||
| + | |||
| + | < | ||
| + | cd .. | ||
| + | python Make_input data | ||
| + | </ | ||
| + | Now inputdata.txt should pick up your xAOD files. | ||
| + | |||
| + | |||
| Now the input file is ready and we run the example as: | Now the input file is ready and we run the example as: | ||
| Line 269: | Line 333: | ||
| To do this we will need a number of changes: | To do this we will need a number of changes: | ||
| - | 1) We need to link several ATLAS packages. | + | 1) We need to link several ATLAS packages |
| < | < | ||
| Line 277: | Line 341: | ||
| in " | in " | ||
| - | 2) Then we need to modify 2 places to put histograms | + | 2) Then we need to modify 2 places to put histograms |
| <code python> | <code python> | ||
| Line 329: | Line 393: | ||
| TBrowser a | TBrowser a | ||
| </ | </ | ||
| - | and look at the histograms | + | and look at the histograms |
asc/tutorials/2014october28.txt · Last modified: 2014/10/29 13:55 by asc
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