Enhancement: Reconsider default names for Ratio-interval parameters

⚠️ Blocked until hackathon starts. Please don't claim or start this yet — it will be moved out of the Blocked column on the aNCA project board when the hackathon begins.

Description

When ratio parameters are auto-generated without a custom PPTESTCD, the default name format is RA{test_parameter} (e.g., RAAUCINT_0-12). For interval parameters with two intervals, this produces confusing names like MRAUCINT_0-12_0-12 that are hard to interpret.

The naming should be reconsidered to be more readable — e.g., separating the test/ref intervals clearly or using a different delimiter.

Where in the app

1. Go to NCA > Setup > Ratio Calculations
2. Add a ratio with two interval parameters (e.g., AUCINT_0-12 as test and AUCINT_0-24 as ref)
3. Leave the custom PPTESTCD field empty
4. Run NCA → observe the auto-generated name in the Results table

Files to modify

Current auto-naming logic

PPTESTCD = if (!is.null(custom_pptestcd)) {
  custom_pptestcd
} else {
  ifelse(n > 1, paste0("RA", test_parameter, " (mean)"), paste0("RA", test_parameter))
}

Suggested approach

Include both test and ref parameter names in the auto-generated PPTESTCD with a clear delimiter, e.g.:

• RA_AUCINT_0-12_vs_AUCINT_0-24 instead of RAAUCINT_0-12
• Or RA_AUCINT(0-12/0-24) — discuss preferred format

This is a naming convention decision — propose a format and get team agreement before implementing.

Definition of Done

• Auto-generated ratio PPTESTCDs are readable for interval parameters
• Non-interval ratio names are unaffected or also improved
• All existing tests pass

Context

Medium issue for the Hackathon Hub. Requires understanding the ratio calculation pipeline in R/ratio_calculations.R.

Start in R/ratio_calculations.R around lines 214–216 and trace how test_parameter, ref parameters, and custom_pptestcd feed the generated PPTESTCD. Review the ratio calculation pipeline and discuss the preferred delimiter or naming convention with the team before implementing. Confirm that interval names are readable, non-interval behavior is addressed as intended, and all existing tests pass.