Function calculate_all 

pub fn calculate_all(
    peaks: &[f32],
    troughs: &[f32],
    switch_times: &[DateTime<Utc>],
    mv_sign_init: i8,
    direction: ControllerDirection,
    config: LoopConfig,
    pv_range: PvRange,
    template: &DcsTemplate,
    compat: TuningMathCompat,
) -> [(TuningResult, PidParameters); 3]

The top-level entry point: computes the PID parameters for all three response levels from a completed MRFT run, in one call. Composes measure_oscillation (once) with calculate_tuning_result and calculate_pid_parameters (once per ResponseLevel). Pure port of MRFTcompletionActions’s call into TuningConstantsCalc + CalculatePIDparameters.

Returns both the intermediate TuningResult (Kp/Ti/Td, DCS-unit-independent) and the final PidParameters (in the template’s own units) for each response level, since callers that persist a run (e.g. bhtune-cli’s tune command, via bhtune_db::TuneResultRow::from_calculated) need both — the schema records the control-theory result alongside the exact values it derived for the connected DCS.