https://github.com/cran/RandomFields
Tip revision: e994a4415e67fa60cbfd3f208aaab20872521c0b authored by Martin Schlather on 14 February 2019, 21:02:19 UTC
version 3.3
version 3.3
Tip revision: e994a44
RPspecific.Rd
\name{Specific}
\alias{Specific}
\alias{RPspecific}
\title{Methods that are specific to certain covariance models}
\description{
This model determines that the (Gaussian) random field should
be modelled by a particular method that is specific to the given
covariance model.
}
\usage{
RPspecific(phi, boxcox)
}
\arguments{
\item{phi}{object of class \code{\link[=RMmodel-class]{RMmodel}};
specifies the covariance model to be simulated.}
\item{boxcox}{the one or two parameters of the box cox transformation.
If not given, the globally defined parameters are used.
See \command{\link{RFboxcox}} for details.
}
% \item{loggauss}{optional arguments; same meaning as for
% \command{\link{RPgauss}}.}
}
\details{
\code{RPspecific} is used for specific algorithms or specific features
for simulating certain covariance functions.
\itemize{ % i.W. alle Modele mit struct und do Funktion
\item{\command{\link{RMplus}}}{
is able to simulate separately
the fields given by its summands. This is necessary, e.g., when
a trend model \command{\link{RMtrend}} is involved.
}
\item{\command{\link{RMmult}}} {
for Gaussian random fields only.
\command{RMmult} simulates the random fields
of all the components and multiplies them. This is repeated
several times and averaged.
}
\item{\command{\link{RMS}}}{
Then, for instance,
\code{sqrt(var)} is multiplied onto the (Gaussian) random
field after the field has been simulated.
Hence, when \code{var} is random, then for each realization
of the Gaussian field (for \code{n>1} in \command{\link{RFsimulate}})
a new realization of \code{var} is used.
Further, new coordinates are created where the old coordinates
have been divided by the \code{scale} and/or multiplied with the
\code{Aniso} matrix or a \code{proj}ection has been performed.
\code{\link{RPspecific}(\link{RMS}())} is called internally when
the user wants to simulate \code{Aniso}tropic fields with
isotropic methods, e.g. \command{\link{RPtbm}}.
}
\item{\command{\link{RMmppplus}}}{
}
\item{\command{\link{RMtrend}}}{
}
% \item{\command{\link{RM}}}{}
}
Note that \code{RPspecific} applies only to the first model or
operator in the argument \code{phi}.
}
\value{
\command{RPspecific} returns an object of class \code{\link[=RMmodel-class]{RMmodel}}.
}
\references{
\itemize{
\item
Schlather, M. (1999) \emph{An introduction to positive definite
functions and to unconditional simulation of random fields.}
Technical report ST 99-10, Dept. of Maths and Statistics,
Lancaster University.
}
}
\me
\examples{\dontshow{StartExample()}
RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set
## RFoptions(seed=NA) to make them all random again
## example for implicit use
model <- RMgauss(var=10, s=10) + RMnugget(var=0.1)
plot(model)
plot(RFsimulate(model=model, 0:10, 0:10, n=4))
## The following function shows the internal structure of the model.
## In particular, it can be seen that RPspecific is applied to RMplus.
RFgetModelInfo(level=0, which="internal")
## example for explicit use: every simulation has a different variance
model <- RPspecific(RMS(var=unif(min=0, max=100), RMgauss()))
x <- seq(0,50,0.02)
plot(RFsimulate(model, x=x, n=4), ylim=c(-15,15))
\dontshow{FinalizeExample()}}
\seealso{ \link{Gaussian},
\link{RP}.
}
\keyword{methods}