Multi-rate Simulation

PlantSimEngine uses Dates.Period values for model cadence and temporal input windows. The same scene can run leaf biophysics hourly and a summary model daily.

daily = ModelSpec(
    DailySummary();
    name=:daily_summary,
    on=One(scale=:Leaf),
    inputs=(
        :assimilation => One(
            within=Self(),
            application=:energy_balance,
            var=:A,
            policy=Integrate(),
            window=Day(1),
        ),
        :temperature => One(
            within=Self(),
            application=:energy_balance,
            var=:Tₗ,
            policy=Aggregate(),
            window=Day(1),
        ),
    ),
    every=ClockSpec(24.0, 24.0),
)

Hourly applications use every=Hour(1). At compilation, PlantSimEngine resolves the source application and creates typed temporal streams. The daily consumer receives integrated assimilation and mean temperature without changing either producer model.

every=Day(1) runs every 24 hourly steps with the default phase. Use ClockSpec(24.0, 24.0) when the daily consumer should run at the end of each 24-hour window.

Available policies are HoldLast, Interpolate, Integrate, and Aggregate. Use MaxReducer() or MinReducer() with Aggregate for daily extrema.

PlantBiophysics also declares timestep hints:

using PlantBiophysics, PlantSimEngine, Dates
(energy=PlantSimEngine.timestep_hint(Monteith()),
 photosynthesis=PlantSimEngine.timestep_hint(Fvcb()))

(energy = (required = (Dates.Minute(1), Dates.Hour(2)), preferred = Dates.Hour(1)), photosynthesis = (required = (Dates.Minute(1), Dates.Hour(6)), preferred = Dates.Hour(1)))

Scenario-level every=... is authoritative; hints validate whether an inferred cadence is scientifically supported.