SpaDES.core (version 2.0.5)

params: Get and set simulation parameters

Description

params, P and Par (an active binding, like "mod") access the parameter slot in the simList. params has a replace method, so can be used to update a parameter value.

Usage

params(sim)
# S4 method for simList
params(sim)
params(sim) <- value
# S4 method for simList
params(sim) <- value
P(sim, param, module)
P(sim, param, module) <- value
parameters(sim, asDF = FALSE)
# S4 method for simList
parameters(sim, asDF = FALSE)

Value

Returns or sets the value of the slot from the simList object.

Arguments

sim

A simList object from which to extract element(s) or in which to replace element(s).

value

The parameter value to be set (in the corresponding module and param).

param

Optional character string indicating which parameter to choose.

module

Optional character string indicating which module params should come from.

asDF

Logical. For parameters, if TRUE, this will produce a single data.frame of all model parameters. If FALSE, then it will return a data.frame with 1 row for each parameter within nested lists, with the same structure as params.

Details

parameters will extract only the metadata with the metadata defaults, NOT the current values that may be overwritten by a user. See examples.

See Also

SpaDES.core-package, specifically the section 1.2.1 on Simulation parameters.

Other functions to access elements of a 'simList' object: .addDepends(), checkpointFile(), envir(), events(), globals(), inputs(), modules(), objs(), packages(), paths(), progressInterval(), times()

Examples

s <- simInit()
# add a parameter to tmp module
params(s)$tmp <- list(a = 1)

# Only work inside a module, inside a function with `sim` is an argument
# P(s, "a") # get "a" parameter inside the current module
# Par$a     # same. Get "a" parameter inside the current module

if (requireNamespace("NLMR", quietly = TRUE) &&
    requireNamespace("SpaDES.tools", quietly = TRUE)) {
  opts <- options("spades.moduleCodeChecks" = FALSE) # not necessary for example
  modules <- list("randomLandscapes")
  paths <- list(modulePath = getSampleModules(tempdir()))
  mySim <- simInit(modules = modules, paths = paths,
                   params = list(.globals = list(stackName = "landscape")))

  # update some parameters using assignment -- currently only params will work
  params(mySim)$randomLandscapes$nx <- 200
  params(mySim)$randomLandscapes$ny <- 200

  parameters(mySim) # Does not contain these user overridden values

  # These next 2 are same here because they are not within a module
  P(mySim)          # Does contain the user overridden values
  params(mySim)     # Does contain the user overridden values

  # NOTE -- deleting a parameter will affect params and P, not parameters
  params(mySim)$randomLandscapes$nx <- NULL
  params(mySim)$randomLandscapes$ny <- NULL

  parameters(mySim) # Shows nx and ny

  # These next 2 are same here because they are not within a module
  P(mySim)          # nx and ny are Gone
  params(mySim)     # nx and ny are Gone

  options(opts) # reset
}