RFsimulate: Simulation of Random Fields

In geostatsp: Geostatistical Modelling with Likelihood and Bayes

Simulation of Random Fields

Description

This function simulates conditional and unconditional Gaussian random fields, calling the function in the RandomFields package of the same name.

Usage

## S4 method for signature 'ANY,SpatRaster'
RFsimulate(model, x,	data=NULL,
 err.model=NULL, n = 1, ...)
## S4 method for signature 'numeric,SpatRaster'
RFsimulate(model, x,data=NULL,
 err.model=NULL, n = 1, ...)
## S4 method for signature 'numeric,SpatVector'
RFsimulate(model, x, data=NULL, 
err.model=NULL, n = 1, ...)
## S4 method for signature 'RMmodel,SpatRaster'
RFsimulate(model, x, data=NULL, 
 err.model=NULL, n = 1, ...)
## S4 method for signature 'RMmodel,SpatVector'
RFsimulate(model, x, data=NULL, 
 err.model=NULL, n = 1, ...)
## S4 method for signature 'matrix,SpatRaster'
RFsimulate(model, x, 	data=NULL, 
 err.model=NULL, n = nrow(model), ...)
## S4 method for signature 'matrix,SpatVector'
RFsimulate(model, x,	data=NULL, 
	err.model=NULL, n = nrow(model), ...)
## S4 method for signature 'data.frame,ANY'
RFsimulate(model, x,	data=NULL, 
	err.model=NULL, n = nrow(model), ...)
modelRandomFields(param, includeNugget=FALSE)

Arguments

model	object of class \Sexpr[results=rd]{c( '\\\code{RMmodel}', '\\\command{\\\\link[RandomFields]{RMmodel}}' )[1+requireNamespace('RandomFields', quietly=TRUE)]}, a vector of named model parameters, or a matrix where each column is a model parameter
x	Object of type SpatRaster or SpatVector.
data	For conditional simulation and random imputing only. If data is missing, unconditional simulation is performed. Object of class SpatVector; coordinates and response values of measurements in case that conditional simulation is to be performed
err.model	For conditional simulation and random imputing only. Usually err.model=RMnugget(var=var), or not given at all (error-free measurements).
n	number of realizations to generate.
...	for advanced use: further options and control parameters for the simulation that are passed to and processed by \Sexpr[results=rd]{c( '\\\code{RFoptions} in the \\\code{RandomFields} package', '\\\command{\\\\link[RandomFields]{RFoptions}}' )[1+requireNamespace('RandomFields', quietly=TRUE)]}
param	A vector of named parameters
includeNugget	If FALSE, the nugget parameter is ignored.

Details

If model is a matrix, a different set of parameters is used for each simulation. If data has the same number of columns as model has rows, a different column i is used with parameters in row i.

Value

An object of the same class as x.

Author(s)

Patrick E. Brown [e-mail]

See Also

\Sexpr[results=rd]{c( '\\\code{RFsimulate} in the \\\code{RandomFields} package', '\\\command{\\\\link[RandomFields]{RFsimulate}}' )[1+requireNamespace('RandomFields', quietly=TRUE)]}

Examples

library('geostatsp')

# exclude this line to use the RandomFields package
options(useRandomFields = FALSE)

model1 <- c(var=5, range=1,shape=0.5)


myraster = rast(nrows=20,ncols=30,extent = ext(0,6,0,4), 
	crs="+proj=utm +zone=17 +datum=NAD27 +units=m +no_defs")

set.seed(0) 

simu <- RFsimulate(model1, x=myraster, n=3)

plot(simu[['sim2']])

xPoints = suppressWarnings(as.points(myraster))
# conditional simulation
firstSample = RFsimulate(
	c(model1, nugget=1), 
	x=xPoints[seq(1,ncell(myraster), len=100), ],
	n=3
)

secondSample = RFsimulate(
	model = cbind(var=5:3, range=seq(0.05, 0.25, len=3), shape=seq(0.5, 1.5, len=3)),
  err.model = 1,
	x= myraster,
	data=firstSample,n=4
)

plot(secondSample)

geostatsp documentation built on Dec. 24, 2024, 3 a.m.