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Class <ArgSpec>

Source: R/class-ArgSpec.R
ArgSpec-class.Rd

An S4 class for specifying the characteristics of a function argument.

Details

<ArgSpec> defines the properties of a function's argument, such as its name, type, value or probability distribution, measurement units and general description.

At a lower level,<ArgSpec> interacts with the VarFn class to define parameters for user-specified function that determine the value of a model variable at each simulation iteration. At a higher level, it ensures model robustness linking function arguments to the IBM's simulation infrastructure.

Slots

name

character, the name of the argument.

type

character, the expected type of argument within roamR's IBM context. Must be one of:

  • "driver": An argument linked to an existing driver; its value is determined by the agent's status (e.g. location) at the current simulation step.

  • "body_mass": Refers to the agent’s body mass at the current simulation step.

  • "time_at_state": An argument related to time spent by the agent in a given state during the current simulation time step.

  • "constant": The argument has a fixed value across simulations.

  • "random": The argument is stochastic and it's value is dictated by a probability distribution.

value

the fixed value assigned to the argument. Required only if type = "constant".

driver_id

character, required if type = "driver"; specifies the ID assigned to a given driver. This assumes the existence of a <Driver> object with a matching ID during the IBM's initialization phase (via rmr_initiate()). Failing that, initialization will not be successful.

state_id,

character, required if type = "time_at_state"; specifies the ID of the referred state. Assumes the existence of a <State> object with a matching ID during the IBM's initialization phase (via rmr_initiate()).

description

character string, a brief explanation of the argument's purpose.

distr

Inherited from parent class <VarDist>, an object of class <distribution>. Required if type = "random", representing the probability distribution associated with the argument's value.

units

Inherited from parent class <VarDist>. A character string defining the measurement unit for the argument, either as a name (e.g. "grams") or a symbol (e.g. "m/s"). Units must be recognized by the units::valid_udunits() database.

See also

Helper function ArgSpec() to construct <ArgSpec> objects