Model switching

One of the main objective of PlantSimEngine is allowing users to switch between model implementations for a given process without making any change to the PlantSimEngine codebase.

The package was designed around this idea to make easy changes easy and efficient. Switch models in the ModelList, and call the run! function again. No other changes are required if no new variables are introduced.

A first simulation as a starting point

With a working environment, let's create a ModelList with several models from the example scripts in the examples folder:

Importing the models from the scripts:

using PlantSimEngine
# Import the examples defined in the `Examples` sub-module:
using PlantSimEngine.Examples

Coupling the models in a ModelList:

models = ModelList(
    ToyLAIModel(),
    Beer(0.5),
    ToyRUEGrowthModel(0.2),
    status=(TT_cu=cumsum(meteo_day.TT),),
)

We can the simulation by calling the run! function with meteorology data. Here we use an example data set:

meteo_day = CSV.read(joinpath(pkgdir(PlantSimEngine), "examples/meteo_day.csv"), DataFrame, header=18)

We can now run the simulation:

output_initial = run!(models, meteo_day)

TimeStepTable{Status{(:TT_cu, :LAI, :aPPFD,...}(365 x 5):
╭─────┬──────────┬────────────┬───────────┬────────────┬───────────────────╮
│ Row │    TT_cu │        LAI │     aPPFD │    biomass │ biomass_increment │
│     │  Float64 │    Float64 │   Float64 │    Float64 │           Float64 │
├─────┼──────────┼────────────┼───────────┼────────────┼───────────────────┤
│   1 │      0.0 │ 0.00554988 │ 0.0396961 │ 0.00793922 │        0.00793922 │
│   2 │      0.0 │ 0.00554988 │   0.02173 │  0.0122852 │          0.004346 │
│   3 │      0.0 │ 0.00554988 │ 0.0314899 │  0.0185832 │        0.00629798 │
│   4 │      0.0 │ 0.00554988 │ 0.0390834 │  0.0263999 │        0.00781668 │
│   5 │      0.0 │ 0.00554988 │ 0.0454514 │  0.0354902 │        0.00909028 │
│   6 │      0.0 │ 0.00554988 │ 0.0472677 │  0.0449437 │        0.00945354 │
│   7 │      0.0 │ 0.00554988 │   0.04346 │  0.0536357 │        0.00869201 │
│   8 │      0.0 │ 0.00554988 │ 0.0469832 │  0.0630324 │        0.00939665 │
│   9 │      0.0 │ 0.00554988 │ 0.0291703 │  0.0688664 │        0.00583406 │
│  10 │      0.0 │ 0.00554988 │ 0.0140052 │  0.0716675 │        0.00280105 │
│  11 │      0.0 │ 0.00554988 │ 0.0505283 │  0.0817731 │         0.0101057 │
│  12 │      0.0 │ 0.00554988 │ 0.0405277 │  0.0898787 │        0.00810554 │
│  13 │   0.5625 │ 0.00557831 │ 0.0297814 │   0.095835 │        0.00595629 │
│  14 │ 0.945833 │ 0.00559777 │ 0.0433269 │     0.1045 │        0.00866538 │
│  15 │ 0.979167 │ 0.00559946 │ 0.0470271 │   0.113906 │        0.00940542 │
│  ⋮  │    ⋮     │     ⋮      │     ⋮     │     ⋮      │         ⋮         │
╰─────┴──────────┴────────────┴───────────┴────────────┴───────────────────╯
                                                            350 rows omitted

Switching one model in the simulation

Now what if we want to switch the model that computes growth ? We can do this by simply replacing the model in the ModelList, and PlantSimEngine will automatically update the dependency graph, and adapt the simulation to the new model.

Let's switch ToyRUEGrowthModel with ToyAssimGrowthModel:

models2 = ModelList(
    ToyLAIModel(),
    Beer(0.5),
    ToyAssimGrowthModel(), # This was `ToyRUEGrowthModel(0.2)` before
    status=(TT_cu=cumsum(meteo_day.TT),),
)

ToyAssimGrowthModel is a little bit more complex than ToyRUEGrowthModel](@ref), as it also computes the maintenance and growth respiration of the plant, so it has more parameters (we use the default values here).

We can run a new simulation and see that the simulation's results are different from the previous simulation:

output_updated = run!(models2, meteo_day)

TimeStepTable{Status{(:TT_cu, :LAI, :aPPFD,...}(365 x 8):
╭─────┬──────────┬────────────┬───────────┬─────────────────────┬────────────┬──
│ Row │    TT_cu │        LAI │     aPPFD │ carbon_assimilation │         Rm │ ⋯
│     │  Float64 │    Float64 │   Float64 │             Float64 │    Float64 │ ⋯
├─────┼──────────┼────────────┼───────────┼─────────────────────┼────────────┼──
│   1 │      0.0 │ 0.00554988 │ 0.0396961 │          0.00793922 │ 0.00396961 │ ⋯
│   2 │      0.0 │ 0.00554988 │   0.02173 │            0.004346 │   0.002173 │ ⋯
│   3 │      0.0 │ 0.00554988 │ 0.0314899 │          0.00629798 │ 0.00314899 │ ⋯
│   4 │      0.0 │ 0.00554988 │ 0.0390834 │          0.00781668 │ 0.00390834 │ ⋯
│   5 │      0.0 │ 0.00554988 │ 0.0454514 │          0.00909028 │ 0.00454514 │ ⋯
│   6 │      0.0 │ 0.00554988 │ 0.0472677 │          0.00945354 │ 0.00472677 │ ⋯
│   7 │      0.0 │ 0.00554988 │   0.04346 │          0.00869201 │   0.004346 │ ⋯
│   8 │      0.0 │ 0.00554988 │ 0.0469832 │          0.00939665 │ 0.00469832 │ ⋯
│   9 │      0.0 │ 0.00554988 │ 0.0291703 │          0.00583406 │ 0.00291703 │ ⋯
│  10 │      0.0 │ 0.00554988 │ 0.0140052 │          0.00280105 │ 0.00140052 │ ⋯
│  11 │      0.0 │ 0.00554988 │ 0.0505283 │           0.0101057 │ 0.00505283 │ ⋯
│  12 │      0.0 │ 0.00554988 │ 0.0405277 │          0.00810554 │ 0.00405277 │ ⋯
│  13 │   0.5625 │ 0.00557831 │ 0.0297814 │          0.00595629 │ 0.00297814 │ ⋯
│  14 │ 0.945833 │ 0.00559777 │ 0.0433269 │          0.00866538 │ 0.00433269 │ ⋯
│  15 │ 0.979167 │ 0.00559946 │ 0.0470271 │          0.00940542 │ 0.00470271 │ ⋯
│  ⋮  │    ⋮     │     ⋮      │     ⋮     │          ⋮          │     ⋮      │ ⋱
╰─────┴──────────┴────────────┴───────────┴─────────────────────┴────────────┴──
                                                  3 columns and 350 rows omitted

And that's it! We can switch between models without changing the code, and without having to recompute the dependency graph manually. This is a very powerful feature of PlantSimEngine!💪