NLMR (version 1.1)

nlm_fbm: nlm_fbm

Description

Creates a two-dimensional fractional Brownian motion neutral landscape model.

Usage

nlm_fbm(
  ncol,
  nrow,
  resolution = 1,
  fract_dim = 1,
  user_seed = NULL,
  rescale = TRUE,
  ...
)

Arguments

ncol

[numerical(1)] Number of columns forming the raster.

nrow

[numerical(1)] Number of rows forming the raster.

resolution

[numerical(1)] Resolution of the raster.

fract_dim

[numerical(1)] The fractal dimension of the process (0,2)

user_seed

[numerical(1)] Set random seed for the simulation

rescale

[numeric(1)] If TRUE (default), the values are rescaled between 0-1.

...

Other options to RandomFields::RFoptions, especially if using a fractal dimension between ~ 1.6 and 1.9 one must set the option modus_operandi = "sloppy".

Value

RasterLayer

Details

Neutral landscapes are generated using fractional Brownian motion, an extension of Brownian motion in which the amount of correlation between steps is controlled by frac_dim. A high value of frac_dim produces a relatively smooth, correlated surface while a low value produces a rough, uncorrelated one.

References

Travis, J.M.J. & Dytham, C. (2004). A method for simulating patterns of habitat availability at static and dynamic range margins. Oikos , 104, 410<U+2013>416.

Martin Schlather, Alexander Malinowski, Peter J. Menck, Marco Oesting, Kirstin Strokorb (2015). nlm_fBm. Journal of Statistical Software, 63(8), 1-25. URL http://www.jstatsoft.org/v63/i08/.

Examples

# NOT RUN {
# simulate fractional brownian motion
fbm_raster  <- nlm_fbm(ncol = 20, nrow = 30, fract_dim = 0.8)

# }
# NOT RUN {
# visualize the NLM
landscapetools::show_landscape(fbm_raster)

# }
# NOT RUN {
# }