Difference between revisions of "Running GSIM CLAS simulation"
From Hall A Wiki
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* to run the first XXXX events through the simulation, modify the '''ffread.in''' file so that it triggers XXXX events | * to run the first XXXX events through the simulation, modify the '''ffread.in''' file so that it triggers XXXX events | ||
− | * then execute the shell script that runs GSIM | + | * then execute the shell script that runs GSIM with e.g. '''12_100GeV.evt''' |
− | ./gsim_Batch.csh | + | ./gsim_Batch.csh 100GeV |
* or simply use the run command | * or simply use the run command | ||
− | RunGSIM | + | RunGSIM 100GeV |
* '''gsim_*.bos''' contains the data 'collected' by CLASS (ADC/TDC) | * '''gsim_*.bos''' contains the data 'collected' by CLASS (ADC/TDC) |
Revision as of 10:42, 12 April 2015
Contents
- 1 GSIM Inventory
- 2 Running GSIM
- 2.1 Setting an Event Generator and create events file
- 2.2 Converting generated data files to GEANT-3 format input
- 2.3 Running generated events through a CLASS GEANT-3 simulation
- 2.4 Converting the GSIM output file to ROOT
- 2.5 Writing the physical tree
- 2.6 Observing the output ROOT TTree
- 2.7 Running GSIM in interactive mode
GSIM Inventory
- GSIM directory is to be located on the farm, at a large enough work disk. An example of the simulation inventory can be found at
/work/halla/e07006/disk1/Erez/gsim (will be used for the remainder of the documentation as $GSIM)
- To get directly to the GSIM location an alias was set, so simply type
GoGSIM
Running GSIM
Setting an Event Generator and create events file
- The simple kinematic event generator we use at TAU is based on actual data:
e-e'p events in which 1 proton was detect serve as baseline to generation of a second proton, using the c.m. kinematics calculation
- For jets/showers, PYTHIA and Lepto64 are used as the base-line event generator for GSIM
- The existing EG is a ROOT macro located under $GSIM/EventGenerator/ directory.
Setting Event Generator
- The EG should be modified for the specific solid target. An example for 12C can be found at
$GSIM/EventGenerator/eep_EG.C
Generate the Events
- To build the event generator use the build compilation command, e.g.
root -l eep_EG.C
(the result: an executable event generator e.g. lepto_exe/LeptoC.exe)
Look at the generated distributions
- A utility for observing the generated data exist in the main EG directory $GSIM/EventGenerator/LeptoRoot
- Port the data file into the utility directory (cp the file to the right location)
- A perl script is used to write it in the right format
rm data.dat ./leptoroot.pl < C.dat > data.dat
(the result: a different (just numbers) data file data.dat)
- An executable is then used to write the data into a ROOT TTree
./leptoroot
(the result: a ROOT file LeptoRoot/data.root that will enable you to observe the generated distributions)
Converting generated data files to GEANT-3 format input
- port the generated-events data file (in this example C.txt) to the converter utility and convert it. e.g.
./txt2part -m -o12_100GeV.evt < 12_100GeV.txt
(the result: a part file mctk.evt suitable for GSIM)
Running generated events through a CLASS GEANT-3 simulation
running GSIM with the generated events
- to run the first XXXX events through the simulation, modify the ffread.in file so that it triggers XXXX events
- then execute the shell script that runs GSIM with e.g. 12_100GeV.evt
./gsim_Batch.csh 100GeV
- or simply use the run command
RunGSIM 100GeV
- gsim_*.bos contains the data 'collected' by CLASS (ADC/TDC)
- gpp_*.bos incorporates preprocessing to add smearing of the data
- outfile_* is the physical data after REConstruction SYStem analyzed it
Look at the output files
- using COUNTBS one could count the number of events, e.g.
./countbs gsimtest.bos
(Note the first additional two events are header and are not to be accounted)
- using BOSDUMP code, one can look at the data from the terminal, e.g.
./bosdump gsimtest.bos ./bosdump gpp_test.bos
Converting the GSIM output file to ROOT
- this is the easy part now. For an output file named outfile1 e.g., use
./WriteRootDst -o output.root -GSIM outfile1
(the result: a root file /output.root)
Writing the physical tree
- The same way used to write the data file (utilizing write_tree.cxx) an executable is generated from write_simulation.cxx
- write_simulation.cxx, apart from writing the EVNT bank data, also writes GSIM data
- An example can be found at /u/home/cohen/Clas/WriteTreeEG2
- A soft link is generated at /w/halla-scifs2/e07006/Erez/gsim/simulate/WriteTree so the only thing ones has to type is
write_simulation
Observing the output ROOT TTree
- The ROOT TTree is called
CLASEVENT
- To look at the data use e.g.
CLASEVENT -> StartViewer()
- The 'collected data' is stored in EVNT.XXXX variables, while the generated data is stored in GSIM.XXXX variables.
Running GSIM in interactive mode
- follow the steps up to ./gsim_test.csh (without executing the shell script!)
- source the necessary environmental set-ups
source /group/clas/builds/environment.csh
- run GSIM
gsim_int -ffread ffread.in -mcin XXXX.evt
(where XXXX.evt is the event file, e.g. mctk.evt)
- inside GSIM you will be prompted to answer a question. disregard it (type \return)
- execute the following commands
switch 1 2 dcut clas 2 0 10 10 0.015 0.015 trig 1