funtuple

name	funtuple
description	Design, review, and verify modern LHCb Run 3 FunTuple configurations and ROOT ntuple outputs. Use for decay fields, caret placement, ThOr functors, FunctorCollection composition, event variables, tuple naming, branch checks, and output inspection. Do not use for legacy DecayTreeTuple or LoKi TupleTools, general DaVinci environment setup, data discovery, or physics-variable choices without user requirements.
license	MIT
metadata	{"era":"run3","maintainer":"LHCb Agent Marketplace contributors","last_verified":"2026-07-02","origin":"original","sources":"https://lhcb-davinci.docs.cern.ch/configuration/davinci_configuration.html; https://lhcb-starterkit-run3.docs.cern.ch/first-analysis-steps/thor-functors/; https://lhcb-starterkit-run3.docs.cern.ch/first-analysis-steps/functor-collections/"}

FunTuple

Configure only required fields and variables, then verify the ROOT output.

Workflow

1. Use $davinci-run3 for the application, input, filter, and YAML options.

2. Match fields to the exact persisted decay descriptor. Use one field name per particle and one caret for each non-head field.

3. Build FunctorCollection objects with current ThOr functors. Keep field keys synchronized with variables and separate event variables.

4. Adapt assets/tuple_job.py and assets/options.example.yaml, then run:

   python scripts/validate_config.py tuple_job.py options.yaml
   lb-run DaVinci/<version> lbexec --dry-run tuple_job:main options.yaml
   lb-run DaVinci/<version> lbexec tuple_job:main options.yaml
   python scripts/verify_output.py tuple.root \
     --tree BToDsPiTuple/DecayTree --branch B_M
   

   The included sample uses DaVinci v65r0 with x86_64_v3-el9-gcc13+detdesc-opt+g.

5. Verify the expected tree, non-zero entries, and all required branches.

Validation

• Require FunTuple_Particles, fields, variables, tuple_name, and inputs.
• Reject DecayTreeTuple, TupleTool*, and default LoKi patterns.
• Record the output file, tree, entry count, branches, release, and command.

Failure handling

• For empty output, check access, process, stream, line, TES path, filter, and descriptor before changing cuts.
• For missing functors, consult the selected release documentation; do not substitute legacy equivalents.

Provenance and scope

Original community templates based on public DaVinci and Run 3 Starterkit interfaces. Physics-variable selection remains an analysis decision.

Sources:

• https://lhcb-davinci.docs.cern.ch/configuration/davinci_configuration.html
• https://lhcb-starterkit-run3.docs.cern.ch/first-analysis-steps/thor-functors/
• https://lhcb-starterkit-run3.docs.cern.ch/first-analysis-steps/functor-collections/