rlandscape: Creates a landscape object based on direct control...

In gregorp/rlandscape: Generates random landscapes with specifiable spatial characteristics

Description

This function takes parameters such as the number of tiles, the proportion of final tiles that are holes and merged, control parameters for choosing random points. It calls random point processes to create a point patter, generates a Voronoi diagram based on the results, modifies the diagram as necessary and outputs a landscape object. pHole and pMerge can be set to any value in [0, 1), but larger values in this range will increase the runtime and are not recommended in general. The number of points picked is scaled up based on pHole and pMerge values so that the number of tiles in the landscape is very close to (usually equal to) sum(n). The control list can include any or all of the following elements:

• lattice, a vector of length 2 containing the number of horizontal and vertical grid lines that lattice points are to be chosen from.

• cluster, a vector of length 2 specifying the number of points per cluster and the cluster spread (standard deviation of a bivariate Gaussian)

• ssi, a single numeric, the inhibition distance for the SSI method.

The makePoints function has defaults for any control parameters not specified.

Usage

rlandscape(n = c(100, 0, 0, 0), hAsp = 1, pMerge = 0.1, pHole = 0.1,
  plot = FALSE, control = list(), filename = NULL, debug = FALSE, ...)

Arguments

n	a vector of the numbers of points to pick with each method: uniform, lattice, cluster, and SSI, respectively. If the vector is of length less than 4 it will be filled out with zeroes.
hAsp	numeric, the horizontal to vertical aspect ratio of the landscape.
pMerge	numeric between 0 and 1, the proportion of tiles in the landscape that have been merged with another tile. In practice, pMerge should be less than 0.5 or so. See 'Details'.
pHole	numeric between 0 and 1, the proportion of tiles in the final landscape that are deleted to become holes. In practie, pHole should be less than 0.5 or so. See 'Details'.
plot	boolean to indicate whether or not a plot is automatically produced. If you save the object returned, you can plot it later.
control	a list of control parameters passed to the makePoints function.
filename	a character string giving the prefix file name to be attached to saved output. Can include a file path. If NULL (the default) nothing will be saved.
debug	Run in debugging mode? (Uses browser().)
...	Additional arguments will be passed to the plot call if appropriate.

Value

A landscape object.

See Also

rland

Examples

myLand <- rlandscape()
myLand$stats
## Not run: 
plot(myLand)
myComplicatedLand <- rlandscape(n = c(20, 80, 40, 10), hAsp = 2, pMerge = 0.3,
    plot = TRUE, control = list(lattice = c(15, 15), ssi = 0.05))

## End(Not run)

gregorp/rlandscape documentation built on May 17, 2019, 8:36 a.m.