Generally useful for model development purposes. Primarily used internally
in e.g., crw
if torus = TRUE
.
wrap(X, bounds, withHeading = FALSE)
SpatVector
, sf
, or matrix of coordinates.
Either a SpatRaster*
, Extent
, or bbox
object defining bounds to wrap around.
logical. If TRUE
, the previous points must be wrapped
also so that the subsequent heading calculation will work.
Default FALSE
. See details.
Object of the same class as X
, but with coordinates updated to reflect the wrapping.
If withHeading
used, then X
must be an sf
or SpatVector
object
that contains two columns, x1
and y1
, with the immediately
previous agent locations.
origDTThreads <- data.table::setDTthreads(2L)
origNcpus <- options(Ncpus = 2L)
xrange <- yrange <- c(-50, 50)
hab <- terra::rast(terra::ext(c(xrange, yrange)))
hab[] <- 0
# initialize agents
N <- 10
# previous points
x1 <- y1 <- rep(0, N)
# initial points
starts <- cbind(x = stats::runif(N, xrange[1], xrange[2]),
y = stats::runif(N, yrange[1], yrange[2]))
# create the agent object # the x1 and y1 are needed for "previous location"
agent <- terra::vect(data.frame(x1, y1, starts), geom = c("x", "y"))
ln <- rlnorm(N, 1, 0.02) # log normal step length
sd <- 30 # could be specified globally in params
if (interactive()) {
# clearPlot()
terra::plot(hab, col = "white")
}
for (i in 1:10) {
agent <- crw(agent = agent, extent = terra::ext(hab), stepLength = ln,
stddev = sd, lonlat = FALSE, torus = FALSE) # don't wrap
if (interactive()) terra::plot(agent[, 1], add = TRUE, col = 1:10)
}
terra::crds(agent) # many are "off" the map, i.e., beyond the extent of hab
#> x y
#> [1,] 6.675128 -55.74968
#> [2,] -40.525784 28.41378
#> [3,] -37.945323 18.14058
#> [4,] -10.143468 31.16253
#> [5,] -59.296128 24.73587
#> [6,] -52.105990 -41.22225
#> [7,] -33.873642 66.28058
#> [8,] 25.918321 -66.73337
#> [9,] -57.863912 29.35450
#> [10,] 71.525150 11.47005
agent <- SpaDES.tools::wrap(agent, bounds = terra::ext(hab))
terra::plot(agent, add = TRUE, col = 1:10) # now inside the extent of hab
#> Error in graphics::plot.xy(list(x = g[, 3], y = g[, 4]), type = "p", pch = pch, col = col, cex = cex, ...): plot.new has not been called yet
# clean up
data.table::setDTthreads(origDTThreads)
options(Ncpus = origNcpus)