SpaDES (version 1.2.0)

wrap: Wrap coordinates or pixels in a torus-like fashion

Description

Generally for model development purposes.

Usage

wrap(X, bounds, withHeading)
"wrap"(X, bounds)
"wrap"(X, bounds)
"wrap"(X, bounds)
"wrap"(X, bounds)
"wrap"(X, bounds)
"wrap"(X, bounds, withHeading)
"wrap"(X, bounds, withHeading)
"wrap"(X, bounds, withHeading)

Arguments

X

A SpatialPoints* object, or matrix of coordinates

bounds

Either a Raster*, Extent, or bbox object defining bounds to wrap around

withHeading

logical. If TRUE, then the previous points must be wrapped also so that the subsequent heading calculation will work. Default FALSE. See details.

Value

Same class as X, but with coordinates updated to reflect the wrapping

Details

If withHeading used, then X must be a SpatialPointsDataFrame that contains two columns, x1 and y1, with the immediately previous agent locations.

Examples

library(raster)
xrange <- yrange <- c(-50, 50)
hab <- raster(extent(c(xrange, yrange)))
hab[] <- 0

# initialize agents
N <- 10

# previous points
x1 <- rep(0, N)
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
agent <- SpatialPointsDataFrame(coords = starts, data = data.frame(x1, y1))


ln <- rlnorm(N, 1, 0.02) # log normal step length
sd <- 30 # could be specified globally in params

if (interactive()) Plot(hab, zero.color = "white", new = TRUE, axes = "L")
for(i in 1:10) {
  agent <- SpaDES::crw(agent = agent,
                         extent = extent(hab), stepLength = ln,
                         stddev = sd, lonlat = FALSE, torus = TRUE)
  if (interactive()) Plot(agent, addTo = "hab", axes = TRUE)
}