Refactor ConformalTrackingV2 Configuration

[Victor-Schwan]

BEGINRELEASENOTES

• fixes: wrong position of fmt off/on statements render them ineffective
• refactors the ConformalTrackingV2 processor configuration in TrackingReco_FCCeeMDI.py

The previous manual string-list definition for the Steps parameter was unwieldy, especially with autoformatting that spread each item across a new line. This change introduces a new utility function, encode_CT_steps_dict_to_legacy_list in py_utils.py, allowing the conformal tracking steps to be defined using a structured Python dictionary.

This significantly improves readability and maintainability by:

• Presenting the configuration in a more intuitive, nested dictionary format.
• Reducing the number of lines occupied by the configuration, particularly after autoformatting.

This is a refactoring effort only; the physics behavior of ConformalTrackingV2 should remain unchanged.

ENDRELEASENOTES

[tmadlener]

Some more structured form for configuring conformal tracking has been introduced in the Gaudi port: https://github.com/key4hep/k4Reco/blob/9a8b181c092e1eb04640869820328a04392a52d6/k4Reco/ConformalTracking/options/runConformalTracking.py#L98-L183

See also key4hep/k4Reco#23 for some more details / discussion. Maybe it's possible to write a similar utility function that converts the dict into the parameters for the wrapped version?

[jmcarcell]

Have a look at this PR: key4hep/CLDConfig#70 where the parameters for tracking for the CLD reconstruction are changed to a more structured format while there are some conversions (look for conformal_tracking_args_marlin) to make sure it still works for Marlin.

[Victor-Schwan]

Some more structured form for configuring conformal tracking has been introduced in the Gaudi port: https://github.com/key4hep/k4Reco/blob/9a8b181c092e1eb04640869820328a04392a52d6/k4Reco/ConformalTracking/options/runConformalTracking.py#L98-L183

See also key4hep/k4Reco#23 for some more details / discussion. Maybe it's possible to write a similar utility function that converts the dict into the parameters for the wrapped version?

Exactly what I was thinking. I didn’t want to spend too much time on it initially, so I just went with the minimal bug fix. But I have now implemented the function or at least I do provide a suggestion :)

[Victor-Schwan]

Have a look at this PR: key4hep/CLDConfig#70 where the parameters for tracking for the CLD reconstruction are changed to a more structured format while there are some conversions (look for conformal_tracking_args_marlin) to make sure it still works for Marlin.

Thank you for bringing this to my attention. It wasn't even on my radar :)
I just skimmed through the CLD PR and noticed a few things:

• There’s no SSOT — for example, the argparse option names are redefined in CLDReconstruction_iosvc, which is part of the user interface. Given that we already have inconsistencies in the utils (as discussed here: Configurability for material plots key4hep/k4geo#392), I think this is quite risky.

In CLDConfig/Tracking/ConformalTracking.py:

• In general, the translation from the dict to the legacy string is implemented twice (in CLDConfig and now in this PR for ILDConfig) — not ideal.

• I think it’s cleaner to move that logic into a separate function, like I did. The details around inserting special characters are a bit distracting where they are for CLD in my humble opinion.

• Also, the following part looks a bit awkwardly implemented, in my opinion:

    for i in range(len(param_dict["collections"])):
        marlin_collections.append(f"{param_dict['collections'][i]}")
        if i < len(param_dict["collections"]) - 1:
            marlin_collections[-1] += ","
    marlin_parameters = []
    for i, (k, v) in enumerate(param_dict["params"].items()):
        marlin_parameters.extend([k, ":", f"{v};"])

    marlin_flags = []
    for i in range(len(param_dict["flags"])):
        marlin_flags.append(f"{param_dict['flags'][i]}")
        if i < len(param_dict["flags"]) - 1:
            marlin_flags[-1] += ","
    marlin_functions = []
    for i in range(len(param_dict["functions"])):
        marlin_functions.append(f"{param_dict['functions'][i]}")
        if i < len(param_dict["functions"]) - 1:
            marlin_functions[-1] += ","

I would guess that pylint would have some suggestions for improvement there.

Let me know what you think :)

[tmadlener]

Thanks. This looks good to me. Could you change the PR title and the release notes to better reflect the changes that are now done with this PR?

[Victor-Schwan]

I suggest to not squash the two commits as they are orthogonal. First, the wrong position of the fmt on/off statements is fixed and later, the CT config is refactored.