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,] -7.359131 47.350120
#> [2,] -36.349039 -4.654296
#> [3,] -39.489929 -15.540533
#> [4,] 31.315504 52.929017
#> [5,] 46.081860 -18.054884
#> [6,] -19.956107 22.787570
#> [7,] -66.934582 -30.752109
#> [8,] -68.224197 18.961591
#> [9,] 24.542212 -62.033998
#> [10,] -40.338536 42.934977
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)