WIP: Allow to generate events before timeframe start (#1768)

Introducing --orbits-early <N> option in MC workflow generation.
This, together with --pregenCollContext, will simulate events in the <N> orbits
before each timeframe start, so that (in particular TPC) readout sees
digits from the previous timeframe.

For now, this just accepts multiple orbits. Finer granularity will come.

(cherry picked from commit 1f7f0dd)

Author: sawenzel

MC/bin/o2dpg_sim_workflow.py

@@ -118,6 +118,8 @@
 parser.add_argument('--combine-tpc-clusterization', action='store_true', help=argparse.SUPPRESS) #<--- useful for small productions (pp, low interaction rate, small number of events)
 parser.add_argument('--first-orbit', default=0, type=int, help=argparse.SUPPRESS)  # to set the first orbit number of the run for HBFUtils (only used when anchoring)
                                                             # (consider doing this rather in O2 digitization code directly)
+parser.add_argument('--orbits-early', default=0, type=int, help=argparse.SUPPRESS) # number of orbits to start simulating earlier
+                                                                                   # to reduce start of timeframe effects in MC --> affects collision context
 parser.add_argument('--sor', default=-1, type=int, help=argparse.SUPPRESS) # may pass start of run with this (otherwise it is autodetermined from run number)
 parser.add_argument('--run-anchored', action='store_true', help=argparse.SUPPRESS)
 parser.add_argument('--alternative-reco-software', default="", help=argparse.SUPPRESS) # power feature to set CVFMS alienv software version for reco steps (different from default)
@@ -596,7 +598,7 @@ def getDPL_global_options(bigshm=False, ccdbbackend=True):
       print('o2dpg_sim_workflow: Error! CM or Beam Energy not set!!!')
       exit(1)
 
-   # Determine interation rate
+   # Determine interaction rate
    signalprefix='sgn_' + str(tf)
    INTRATE=int(args.interactionRate)
    if INTRATE <= 0:
@@ -611,7 +613,10 @@ def getDPL_global_options(bigshm=False, ccdbbackend=True):
    PbPbXSec=8. # expected PbPb cross section
    QEDXSecExpected=35237.5  # expected magnitude of QED cross section
    PreCollContextTask=createTask(name='precollcontext_' + str(tf), needs=precollneeds, tf=tf, cwd=timeframeworkdir, cpu='1')
-   PreCollContextTask['cmd']='${O2_ROOT}/bin/o2-steer-colcontexttool -i ' + signalprefix + ',' + str(INTRATE) + ',' + str(args.ns) + ':' + str(args.ns) + ' --show-context ' + ' --timeframeID ' + str(tf-1 + int(args.production_offset)*NTIMEFRAMES) + ' --orbitsPerTF ' + str(orbitsPerTF) + ' --orbits ' + str(orbitsPerTF) + ' --seed ' + str(TFSEED) + ' --noEmptyTF --first-orbit ' + str(args.first_orbit)
+   PreCollContextTask['cmd']='${O2_ROOT}/bin/o2-steer-colcontexttool -i ' + signalprefix + ',' + str(INTRATE) + ',' + str(args.ns) + ':' + str(args.ns) \
+                              + ' --show-context ' + ' --timeframeID ' + str(tf-1 + int(args.production_offset)*NTIMEFRAMES)                            \
+                              + ' --orbitsPerTF ' + str(orbitsPerTF) + ' --orbits ' + str(orbitsPerTF + args.orbits_early)                                                  \
+                              + ' --seed ' + str(TFSEED) + ' --noEmptyTF --first-orbit ' + str(args.first_orbit - args.orbits_early)
    PreCollContextTask['cmd'] += ' --bcPatternFile ccdb'  # <--- the object should have been set in (local) CCDB
    if includeQED:
       qedrate = INTRATE * QEDXSecExpected / PbPbXSec   # hadronic interaction rate * cross_section_ratio