evtgen_gen.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
 
 
 
 
 
import basf2 as b2
from generators import add_evtgen_generator
from modularAnalysis import setupEventInfo
from modularAnalysis import loadGearbox
from reconstruction import add_mdst_output
from optparse import OptionParser
from ROOT import Belle2
 
parser = OptionParser()
parser.add_option('-n', '--nevents', dest='nevents', default=1000,
                  help='Number of events to process')
parser.add_option('-f', '--file', dest='filename',
                  default='B2Kpi_events.root')
(options, args) = parser.parse_args()
 
# Suppress messages and warnings during processing:
b2.set_log_level(b2.LogLevel.ERROR)
 
 
# generation of 1000 events according to the specified DECAY table
# Y(4S) -> B0 B0bar
# one B0->K+pi-, other generic decay
mypath = b2.create_path()
setupEventInfo(int(options.nevents), mypath)
add_evtgen_generator(mypath, 'signal', Belle2.FileSystem.findFile('arich/examples/B2kpi.dec'))
 
# If the simulation and reconstruction is not performed in the sam job,
# then the Gearbox needs to be loaded with the loadGearbox() function.
loadGearbox(mypath)
 
# dump generated events in MDST format to the output ROOT file
add_mdst_output(mypath, True, options.filename)
 
# process all modules added to the mypath path
b2.process(mypath)
 
# print out the summary
print(b2.statistics)