fitValidation.py

 
 
from tracking import modules
from tracking.run.event_generation import StandardEventGenerationRun
import sys
import logging
from tracking.harvest import refiners
from tracking.harvest.harvesting import HarvestingModule
import ROOT
from ROOT import Belle2
 
from ROOT import gSystem
gSystem.Load('libtracking')
gSystem.Load('libtracking_trackFindingCDC')
 
 
class FitValidationModule(HarvestingModule):
    """Validate the track fit"""
 
    def __init__(
            self,
            mc_track_cands_store_array_name,
            legendre_track_cand_store_array_name,
            output_file_name):
        """Constructor"""
        super().__init__(
            foreach=legendre_track_cand_store_array_name,
            output_file_name=output_file_name)
 
        
        self.mc_track_cands_store_array_name = mc_track_cands_store_array_name
        
        self.legendre_track_cand_store_array_name = legendre_track_cand_store_array_name
 
        
        self.circle_fitter = Belle2.TrackFindingCDC.CDCRiemannFitter.getFitter()
        
        self.fast_fitter = Belle2.TrackFindingCDC.TrackFitter()
 
    def prepare(self):
        """ Initialize the harvester"""
        
        self.cdcHits = Belle2.PyStoreArray("CDCHits")
        return HarvestingModule.prepare(self)
 
    def peel(self, legendre_track_cand):
        """Aggregate the track and MC information for track-fit validation"""
 
        cdc_hit_store_array = self.cdcHits
 
        # observations_variance = Belle2.TrackFindingCDC.CDCObservations2D()
        observations = Belle2.TrackFindingCDC.CDCObservations2D()
        hits = ROOT.std.vector("Belle2::TrackFindingCDC::TrackHit*")()
 
        cdc_hit_ids = legendre_track_cand.getHitIDs(Belle2.Const.CDC)
        for cdc_hit_id in cdc_hit_ids:
            cdc_hit = cdc_hit_store_array[cdc_hit_id]
 
            # We will only use the axial hits here as the FastFit can only process axial hits too
            if cdc_hit.getISuperLayer() % 2 == 0:
                cdc_wire_hit = Belle2.TrackFindingCDC.CDCWireHit(cdc_hit)
 
                wireRefPos2D = cdc_wire_hit.getRefPos2D()
                drift_length = cdc_wire_hit.getRefDriftLength()
                observations.append(wireRefPos2D.x(), wireRefPos2D.y(), 0, 1 / abs(drift_length))
                hits.push_back(Belle2.TrackFindingCDC.TrackHit(cdc_wire_hit))
 
        # Viktors method
        track_par = ROOT.std.pair("double, double")()
        ref_point = ROOT.std.pair("double, double")()
        # Careful: viktors result is a reduced chi2
        viktor_chi2 = self.fast_fitter.fitTrackCandidateFast(hits, track_par, ref_point, False) * (hits.size() - 4)
 
        # Riemann without drift variances
        trajectory2D = Belle2.TrackFindingCDC.CDCTrajectory2D()
        self.circle_fitter.update(trajectory2D, observations)
        riemann_chi2 = trajectory2D.getChi2()
 
        return_dict = dict(
            riemann_chi2=riemann_chi2,
            viktor_chi2=viktor_chi2,
        )
 
        return return_dict
 
    
    save_tree = refiners.save_tree(folder_name="tree")
 
 
class FitValidation(StandardEventGenerationRun):
    """Read generated events or generate new events, simulate, fit the tracks and validate"""
 
    def create_path(self):
        """Create and populate the basf2 path"""
 
        main_path = super().create_path()
 
        main_path.add_module("TFCDC_WireHitPreparer")
 
        main_path.add_module(modules.CDCMCFinder())
 
        main_path.add_module(FitValidationModule(mc_track_cands_store_array_name="MCTrackCands",
                                                 legendre_track_cand_store_array_name="MCTrackCands",
                                                 output_file_name="fit_validation.root"))
 
        return main_path
 
 
def main():
    run = FitValidation()
    run.configure_and_execute_from_commandline()
 
 
if __name__ == "__main__":
    logging.basicConfig(stream=sys.stdout, level=logging.INFO, format='%(levelname)s:%(message)s')
    main()