Spatial Discrete Event Simulator
SpaDESis oriented around the construction of spatially explicit models and the use of spatial data.
In Ecology, there are other generic DESs:
More specific DESs
Modules are a convenient way to group events that fit naturally together:
What is contained in one module is highly idiosyncratic .
SpaDES is implemented in a way that facilitates modularity of code:
Thus, modules can be added, removed, or swapped out without needing to recode the rest of the model.
There are many types of modules that may be useful:
Once we see that a module is just a convenient way to group together events, anything can be a module. Can be a single line of code or as many as you want.
… instead of just an R script or function?
allows things to be scheduled
can be published on the web
can estimate unknown parameters
and much more…
A module is an R script with 3 parts:
Metadata - a list of 15 things
doEvent - 2 types of things here
Essentially 2 steps
All the necessary information is contained within the
What might be needed for a DES to run…
- start and stop times - data - paths - which modules to use - parameters - a schedule of events - outputs
We are working with R, so we can use any data structure or file format that R can understand
SpaDES has some helpers for loading data, but in general, the module should be explicit
downloadData("caribouMovementLcc", path = tempdir())
A module takes input data, changes them, and provides outputs
like a function, but with the addition of “time”
Some challenges …
Numerous challenges exist with data
SpaDES doesn’t necessarily solve these issues, but in some cases it helps.