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This guide walks you through running a TPC reconstruction on a real DUNE/ProtoDUNE dataset. After completing these steps you will have a fully reconstructed HDF5 output file containing hits, 2D tracks, 3D tracks, and single hits.

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Prerequisites

  • LARDON installed via Pixi (see Installation)
  • Environment variables configured (see Environment Setup)
  • Access to a raw HDF5 data file on CERN lxplus, FNAL, or locally
1

Source the environment

Set the required environment variables by sourcing the setup script from the lardon repository root:
source set_lardon.sh
This sets LARDON_PATH, LARDON_RECO, and LARDON_PLOT relative to your current directory.
2

Activate the environment

You can run LARDON in two ways:
3

Verify the output

After the run completes, check that the output file was created in $LARDON_RECO:
ls $LARDON_RECO/pdvd_39229_24_*.h5
LARDON prints a reconstruction summary to stdout:
**************
* Reco total *
**************
* Nb of Hits 1234
* Nb of 2D Tracks 56
* Nb of 3D Tracks 12
* Nb of Ghosts 0
* Nb of Single Hits 89
* Nb of PDS Peaks 0
* Nb of PDS Clusters 0
**************

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Example commands

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Single-event TPC reconstruction (PDVD)

Reconstruct event 11 from PDVD run 39229, subfile 24: 
lardon -det pdvd -run 39229 -sub 24 -flow 4 -writer 0 -serv 5 -hash 86/ad -event 11 -out one_event -trk
Output file: $LARDON_RECO/pdvd_39229_24_40_s5_one_event.h5

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All-events TPC reconstruction (PDVD)

Reconstruct all events from PDVD run 39246, subfile 6: 
lardon -det pdvd -run 39246 -sub 6 -out full_example -trk
When both -flow and -writer are 0, you do not need to provide them. The command above omits them.
Output file: $LARDON_RECO/pdvd_39246_6_full_example.h5

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First 10 events from a Coldbox run

lardon -det cbbot -run 37040 -sub 23 -hash 5a/a2 -n 10 -trk -out few_events
Output file: $LARDON_RECO/cbbot_37040_23_few_events.h5

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TPC and PDS reconstruction via XRootD

Reconstruct events 5 and 6 with both TPC and PDS from a remote file: 
lardon -det cbbot -run 37041 -sub 79 \
  -file root://somewhere.abc:1094/directory/raw/data/np02vdcoldbox_raw_run037041_0079_df-s02-d0_dw_0_20250705T130324.hdf5 \
  -n 6 -skip 4 -trk -pds -out evt_5_6_both_reco
When using -file with an XRootD path, LARDON extracts the run number, subfile, detector, dataflow, and writer from the filename automatically. Make sure the XRootD lines are uncommented in set_lardon.sh before using this method.

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Output file naming convention

Output files follow this pattern: 
{detector}_{run}_{sub}{flow_writer_suffix}_{outname}.h5
The flow_writer_suffix is appended only when a non-default dataflow/datawriter/server combination is used. See Output Files for the full HDF5 schema.

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Next steps

Command Reference

Full documentation of every CLI flag and its default value.

Reconstruction Pipeline

How LARDON processes raw data from signal to track.

Configuration

Configure environment variables and detector settings.

Control Plots

Generate event displays and noise plots during reconstruction.

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