In the simInit call, a parameter called .saveObjects can be provided in each module. This must be a character string vector of all object names to save. These objects will then be saved whenever a call to saveFiles is made.




A simList simulation object.


The file names will be equal to the object name plus time(sim) is appended at the end. The files are saved as .rds files, meaning, only one object gets saved per file.

For objects saved using this function, the module developer must create save events that schedule a call to saveFiles.

If this function is used outside of a module, it will save all files in the outputs(sim) that are scheduled to be saved at the current time in the simList.

There are 3 ways to save objects using SpaDES.


It is not possible to schedule separate saving events for each object that is listed in the .saveObjects.

1. Model-level saving

Using the outputs slot in the simInit call. See example in simInit. This can be convenient because it gives overall control of many modules at a time, and it gets automatically scheduled during the simInit call.

2. Module-level saving

Using the saveFiles function inside a module. This must be accompanied by a .saveObjects list element in the params slot in the simList. Usually a module developer will create this method for future users of their module.

3. Custom saving

A module developer can save any object at any time inside their module, using standard R functions for saving R objects (e.g., save or saveRDS). This is the least modular approach, as it will happen whether a module user wants it or not.


# This will save the "caribou" object at the save interval of 1 unit of time
#  in the outputPath location
outputPath <- file.path(tempdir(), "test_save")
times <- list(start = 0, end = 6, "month")
parameters <- list(
  .globals = list(stackName = "landscape"),
  caribouMovement = list(
    .saveObjects = "caribou",
    .saveInitialTime = 1, .saveInterval = 1
  randomLandscapes = list(.plotInitialTime = NA, nx = 20, ny = 20))

modules <- list("randomLandscapes", "caribouMovement")
paths <- list(
  modulePath = system.file("sampleModules", package = "SpaDES.core"),
  outputPath = savePath
mySim <- simInit(times = times, params = parameters, modules = modules,
                 paths = paths)

# The caribou module has a saveFiles(sim) call, so it will save caribou

# remove the files
file.remove(dir(savePath, full.names = TRUE))

# }