SpaDES.tools
packageSpatial contagion is a key phenomenon for spatially explicit simulation models. Contagion can be modelled using discrete approaches or continuous approaches. Several functions assist with these:
adj |
An optimized (i.e., faster) version of
adjacent |
cir |
Identify pixels in a circle around a
SpatialPoints* object |
directionFromEachPoint |
Fast calculation of direction and distance surfaces |
distanceFromEachPoint |
Fast calculation of distance surfaces |
rings |
Identify rings around focal cells (e.g., buffers and donuts) |
spokes |
TO DO: need description |
spread |
Contagious cellular automata |
wrap |
Create a torus from a grid |
Agents have several methods and functions specific to them:
crw |
Simple correlated random walk function |
heading |
Determines the heading between SpatialPoints* |
makeLines |
Makes SpatialLines object for,
e.g., drawing arrows |
move |
A meta function that can currently only take "crw" |
specificNumPerPatch |
Initiate a specific number of agents per patch |
In addition to the vast amount of GIS operations available in R (mostly from
contributed packages such as sp
, raster
, maps
, maptools
and many others), we provide the following GIS-related functions:
equalExtent |
Assess whether a list of extents are all equal |
These functions convert between reduced and mapped representations of the same data. This allows compact representation of, e.g., rasters that have many individual pixels that share identical information.
rasterizeReduced |
Convert reduced representation to full raster |
It is often useful to build dummy maps with which to build simulation models before all data are available. These dummy maps can later be replaced with actual data maps.
gaussMap |
Creates a random map using Gaussian random fields |
randomPolygons |
Creates a random polygon with specified number of classes |
These functions are essentially skeletons and are not fully implemented. They are intended to make translations from SELES. You must know how to use SELES for these to be useful:
agentLocation |
Agent location |
initiateAgents |
Initiate agents into a SpatialPointsDataFrame |
numAgents |
Number of agents |
probInit |
Probability of intiating an agent or event |
transitions |
Transition probability |
SpaDES
packages use the following options
to configure behaviour:
spades.lowMemory
: If true, some functions will use more memory
efficient (but slower) algorithms. Default FALSE
.
Useful links: