Editing Model Parameters

Editing a model involves changing model parameter values. This task can be accomplished via a unified method called edit_model from CoreModel or ApsimModel Class by specifying the model type, name and simulation name.

edit_method function signature

edit_model(model_type: str, simulations: Union[str, list], model_name: str, **kwargs)

Parameters

model_typestr

Type of the model component to modify (e.g., ‘Clock’, ‘Manager’, ‘Soils.Physical’, etc.).

simulationsUnion[str, list], optional

A simulation name or list of simulation names in which to search. Defaults to all simulations in the model.

model_namestr

Name of the model instance to modify.

**kwargsdict

Additional keyword arguments specific to the model type. These vary by component:

  • Weather:

    • weather_file (str): Path to the weather .met file.

  • Clock:

    • Date properties such as Start and End in ISO format (e.g., ‘2021-01-01’).

  • Manager:

    • Variables to update in the Manager script using update_mgt_by_path.

    The parameters in a manager script are specific to each script. See inspect_model_parameters:Inspect Model Parameters for more details. for more details. for more details. on how to inspect and retrieve these paramters without opening the file in a GUI

  • Physical | Chemical | Organic | Water: The supported key word arguments for each model type are given in the table below. Please note the values are layered and thus a str or list is accepted. when a value is supplied as str, then it goes to the top soil layer. In case of a list, value are replaced based on their respective index in the list. As a caution if the length of the list supplied exceeds the available number of layers in the profile, a RuntimeError during model runs will be raised. It is possible to target a specific layer(s) by supplying the location of that layer(s) using indices key word argument, if there is a need to target the bottom layer, use indices  = [-1]

Soil Model Type

Supported key word arguments

Physical

AirDry, BD, DUL, DULmm, Depth, DepthMidPoints, KS, LL15, LL15mm, PAWC, PAWCmm, SAT, SATmm, SW, SWmm, Thickness, ThicknessCumulative

Organic

CNR, Carbon, Depth, FBiom, FInert, FOM, Nitrogen, SoilCNRatio, Thickness

Chemical

Depth, PH, Thickness
  • SurfaceOrganicMatter

    • InitialCNR: (int)

    • InitialResidueMass (int)

  • Report:

    • report_name (str): Name of the report model (optional depending on structure).

    • variable_spec (list[str] or str): Variables to include in the report.

    • set_event_names (list[str], optional): Events that trigger the report.

  • Cultivar:

    • commands (str): APSIM path to the cultivar model to update.

    • values (Any): Value to assign.

    • cultivar_manager (str): Name of the Manager script managing the cultivar, which must contain the CultivarName parameter. Required to propagate updated cultivar values, as APSIM treats cultivars as read-only.

Raises

ValueError

If the model instance is not found, required kwargs are missing, or kwargs is empty.

NotImplementedError

If the logic for the specified model_type is not implemented.

Examples:

from apsimNGpy.core.apsim import ApsimModel
model = ApsimModel(model='Maize')

Edit a cultivar model:

model.edit_model(
    model_type='Cultivar',
    simulations='Simulation',
    commands='[Phenology].Juvenile.Target.FixedValue',
    values=256,
    model_name='B_110',
    cultivar_manager='Sow using a variable rule')

Edit a soil organic matter module:

model.edit_model(
    model_type='Organic',
    simulations='Simulation',
    model_name='Organic',
    Carbon=1.23)

Edit multiple soil layers:

model.edit_model(
    model_type='Organic',
    simulations='Simulation',
    model_name='Organic',
    Carbon=[1.23, 1.0])

Edit solute models:

model.edit_model(
    model_type='Solute',
    simulations='Simulation',
    model_name='NH4',
    InitialValues=0.2)

model.edit_model(
    model_type='Solute',
    simulations='Simulation',
    model_name='Urea',
    InitialValues=0.002)

Edit a manager script:

model.edit_model(
    model_type='Manager',
    simulations='Simulation',
    model_name='Sow using a variable rule',
    population=8.4)

Edit surface organic matter parameters:

model.edit_model(
    model_type='SurfaceOrganicMatter',
    simulations='Simulation',
    model_name='SurfaceOrganicMatter',
    InitialResidueMass=2500)

model.edit_model(
    model_type='SurfaceOrganicMatter',
    simulations='Simulation',
    model_name='SurfaceOrganicMatter',
    InitialCNR=85)

Edit Clock start and end dates:

model.edit_model(
    model_type='Clock',
    simulations='Simulation',
    model_name='Clock',
    Start='2021-01-01',
    End='2021-01-12')

Edit report variables:

model.edit_model(
    model_type='Report',
    simulations='Simulation',
    model_name='Report',
    variable_spec='[Maize].AboveGround.Wt as abw')

Multiple report variables:

model.edit_model(
    model_type='Report',
    simulations='Simulation',
    model_name='Report',
    variable_spec=[
        '[Maize].AboveGround.Wt as abw',
        '[Maize].Grain.Total.Wt as grain_weight'
    ])