Here we have some information for GlobalChi2

About fitter configurations ATLAS Athena Run 3 configuration | Athena Configuration (cern.ch)

Treat infinities/zero values of q/p consistently in the GlobalChi2 fitter : https://its.cern.ch/jira/browse/ATLASRECTS-6213

ALL TODO from https://gitlab.cern.ch/atlas/athena/-/blob/master/Tracking/TrkFitter/TrkGlobalChi2Fitter/src/GlobalChi2Fitter.cxx:

TODO according to coverity elosspar cannot be non NULL here because elosspar is initially NULL and only set in the last loop iteration (i==1) is this intended ? delete elosspar;

TODO eventually track created but not used why ?

TODO fillResiduals assumes that numberOfBrems == number of states with material effects and sigmaDeltaE() > 0 not clear whether fillResiduals has to be adjusted for electrons rather than this

TODO coverity complains about index shadowing the method argument index this is solved by renaming index in this block by param_index

TODO here index really is supposed to refer to the method argument index ?

TODO: Use polymorphism to get rid of these strange types.

TODO coverity complains about a possible null pointer dereferencing in scatstate->... or scatstate2->... it seems to me that if (**it).materialEffects()->deltaE()==0 of the first scatterer than scatstate will be NULL.

TODO Coverity complains about a possible NULL pointer dereferencing in lastmeasstate->... Now an exception is thrown if there is no firstmeastate. Thus if the code here is reached then there should be a firstmeasstate and a lastmeasstate

Firstly, we need to guard against tracks having too few measurement states to perform a good hole search. This is a mechanism that we inherit from the reference hole search. If we have too few states, we return a non-extant result to indicate an error state. TODO: The minimum value of 3 is also borrowed from the reference implementation. It's hardcoded for now, but could be a parameter in the future.

ART, ATN, ClTesting - soft validation tests

ART < AtlasComputing < TWiki (cern.ch)

ART User Manual (cern.ch)

ATNightTesting < AtlasComputing < TWiki (cern.ch)

CITestingFramework < AtlasComputing < TWiki (cern.ch)

iPat Fitter

Twiki for iPat (2007) from Alan: https://twiki.cern.ch/twiki/bin/view/AtlasComputing/IPatRec

reco-validation: https://gitlab.cern.ch/atlas/athena/-/tree/master/MuonSpectrometer/MuonValidation/MuonRecValidation

iPat Fitter is responsible for pattern recognition and track fitting of muons in Inner Detector (ID). It's place in muon track reconstruction process is the following:

1. Search for muons segments in Muon spectrometer (MS);
2. Extrapolation of them to ID;
3. Looking for hits in ID - pattern recognition (iPat);
4. Fitting of hits in ID (iPat);
5. Combining of fits in ID with MS.

Switch off iPat in Recotf.py : preExec='InDetFlags.iPatRec= False’

Main repository for iPat:

1. https://gitlab.cern.ch/atlas/athena/-/tree/master/Tracking/TrkFitter/TrkiPatFitter
2. https://gitlab.cern.ch/atlas/athena/-/tree/master/Tracking/TrkFitter/TrkiPatFitterUtils

Questions for Alan

1. Is iPat doing its own pattern recognition in ID, or it takes patterns, recognised by the standard ID software for pattern recognition?