# Regression test set

The `tests/` tree contains the 13 target configurations used as the reference
regression set for the TRIM.SP-NL modernization. Together they contain 143
energy-configuration points.

The committed `.out` files intentionally retain the banner `TrimSPNL v1.3.2`:
they are the historical RANLUX reference outputs used to check
behavior-preserving refactoring. They should therefore not be mechanically
regenerated or replaced when preparing a new release.

For changes intended to preserve behavior, current RANLUX output should agree
with these references apart from nondeterministic timing fields and quantities
affected by explicitly documented corrections. PCG32 and xoshiro256** generate
different Monte Carlo histories and are therefore compared statistically rather
than by bitwise output identity.

The configurations are:

- `6element_plus_multilayer`
- `7layer_stack`
- `SiO2_Al2O3_TiN_Si_4layer`
- `thin_Au_Cr_Si`
- `Au_Cr_Si_3layer`
- `AlCoCrFeNiTi_6elements`
- `SiO2_Si_2layer`
- `SiO2_1layer`
- `Si_1layer`
- `thin_C_foil`
- `thin_C_Au_C`
- `Li8-Si_1layer`
- `Li8-thin_C_Au_C`

When running an individual case manually, copy the relevant input deck to a
scratch directory first so the committed reference files are not overwritten.
The transport executable accepts an optional RNG backend as its second argument,
for example:

```text
trimspNL run_basename ranlux
trimspNL run_basename pcg32
trimspNL run_basename xoshiro
```

Omitting the second argument selects RANLUX.