Skip to content

workflow

Directory actions

More options

Directory actions

More options

Latest commit

 

History

History
 
 

workflow

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
include/TRKWorkflow
include/TRKWorkflow
 
 
src
src
 
 
CMakeLists.txt
CMakeLists.txt
 
 
README.md
README.md
 
 

README.md

TRK Reconstruction Workflow

This document describes how to run the TRK (ALICE 3 Tracker) reconstruction workflow and provides examples of configuration files.

Overview

The TRK reconstruction workflow performs track reconstruction from simulated hits, producing reconstructed tracks with MC truth labels. The workflow currently supports the track reconstruction from hits using the Cellular Automaton (CA) algorithm. The ouput is stored to a ROOT file for offline analysis (example of QA macro provided in macros/test/CheckTracksCA.C).

Quick Start

Basic Command

o2-alice3-trk-reco-workflow --tracking-from-hits-config config_tracker.json -b

Command Line Options

  • --tracking-from-hits-config <file>: Path to tracking configuration JSON file (required)
  • -b: Batch mode (no GUI)
  • --disable-root-output: Skip writing tracks to ROOT file
  • --help: Show all available options

Configuration File

The tracking configuration is provided via a JSON file that specifies:

  1. Input file paths
  2. Geometry parameters (magnetic field, detector pitch)
  3. Tracking algorithm parameters (can specify multiple iterations)

Example Configuration (config_tracker.json)

{
  "inputfiles": {
    "hits": "o2sim_HitsTRK.root",
    "geometry": "o2sim_geometry.root",
    "mcHeader": "o2sim_MCHeader.root",
    "kinematics": "o2sim_Kine.root"
  },
  "geometry": {
    "bz": 5.0,
    "pitch": [0.001, 0.001, 0.001, 0.001, 0.004, 0.004, 0.004, 0.004, 0.004, 0.004, 0.004]
  },
  "trackingparams": [{
    "NLayers": 11,
    "DeltaROF": 0,
    "LayerZ": [25.1, 25.1, 25.1, 64.2, 64.2, 64.2, 64.2, 64.2, 128.5, 128.5, 128.5],
    "LayerRadii": [0.5, 1.2, 2.5, 7.05, 9.05, 12.05, 20.05, 30.05, 45.05, 60.5, 80.05],
    "LayerxX0": [0.001, 0.001, 0.001, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01],
    "LayerResolution": [0.0003, 0.0003, 0.0003, 0.0003, 0.0012, 0.0012, 0.0012, 0.0012, 0.0012, 0.0012, 0.0012],
    "SystErrorY2": [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
    "SystErrorZ2": [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
    "ZBins": 256,
    "PhiBins": 128,
    "nROFsPerIterations": -1,
    "UseDiamond": false,
    "Diamond": [0.0, 0.0, 0.0],
    "AllowSharingFirstCluster": false,
    "ClusterSharing": 0,
    "MinTrackLength": 7,
    "NSigmaCut": 10,
    "PVres": 0.01,
    "TrackletMinPt": 0.1,
    "TrackletsPerClusterLimit": 2.0,
    "CellDeltaTanLambdaSigma": 0.007,
    "CellsPerClusterLimit": 2.0,
    "MaxChi2ClusterAttachment": 60.0,
    "MaxChi2NDF": 30.0,
    "ReseedIfShorter": 6,
    "MinPt": [0.0, 0.0, 0.0, 0.0],
    "StartLayerMask": 4095,
    "RepeatRefitOut": false,
    "ShiftRefToCluster": true,
    "FindShortTracks": false,
    "PerPrimaryVertexProcessing": false,
    "SaveTimeBenchmarks": false,
    "DoUPCIteration": false,
    "FataliseUponFailure": true,
    "UseTrackFollower": true,
    "UseTrackFollowerTop": false,
    "UseTrackFollowerBot": false,
    "UseTrackFollowerMix": true,
    "TrackFollowerNSigmaCutZ": 1.0,
    "TrackFollowerNSigmaCutPhi": 1.0,
    "createArtefactLabels": false,
    "PrintMemory": false,
    "DropTFUponFailure": false
  }]
}

Note that the trackingparams field can contain multiple sets of parameters for different iterations of the tracking algorithm. The example above shows a single iteration with 11 layers and it is not optimized.

Complete Workflow Example

1. Run Simulation

First, generate simulation data:

o2-sim-serial-run5 -n 200 -g pythia8hi -m TRK --configKeyValues "Diamond.width[0]=0.01;Diamond.width[1]=0.01;Diamond.width[2]=5;TRKBase.layoutML=kTurboStaves;TRKBase.layoutOT=kStaggered;"

This produces, among other files:

  • o2sim_HitsTRK.root
  • o2sim_geometry.root
  • o2sim_MCHeader.root
  • o2sim_Kine.root That will be used by the reconstruction as currently we do not have clusters.

2. Run Reconstruction

Execute the tracking workflow:

o2-alice3-trk-reco-workflow --tracking-from-hits-config config_tracker.json -b

This produces:

  • o2trac_trk.root: Reconstructed tracks with MC labels

3. Run Quality Assurance

Analyze the tracking performance:

root -l
.L CheckTracksCA.C+
CheckTracksCA("o2trac_trk.root", "o2sim_Kine.root", "o2sim_HitsTRK.root", "trk_qa_output.root")