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\name{RMcircular}
\alias{RMcircular}
\title{Circular Covariance Model}
\description{
\command{\link{RMcircular}} is a stationary isotropic covariance model
which is only valid for dimensions \eqn{d \le 2 }{d \le 2 }.
The corresponding covariance function only depends on the distance \eqn{r \ge 0}{r \ge 0} between
two points and is given by
\deqn{C(r) = 1 - 2/\pi (r \sqrt(1-r^2) + arcsin(r)) 1_{[0,1]}(r).}{C(r) = 1 - 2/\pi (r \sqrt(1-r^2) + asin(r)) 1_{[0,1]}(r).}
}
\usage{
RMcircular(var, scale, Aniso, proj)
}
\arguments{
\item{var,scale,Aniso,proj}{optional arguments; same meaning for any
\command{\link{RMmodel}}. If not passed, the above
covariance function remains unmodified.}
}
\details{The model is only valid for dimensions \eqn{d \le 2 }{d \le 2}.
It is a covariance function with compact support
(cf. Chiles, J.-P. and Delfiner, P. (1999), p. 82).
}
\value{
\command{\link{RMcircular}} returns an object of class \code{\link[=RMmodel-class]{RMmodel}}.
}
\references{
\itemize{
\item Chiles, J.-P. and Delfiner, P. (1999)
\emph{Geostatistics. Modeling Spatial Uncertainty.}
New York: Wiley.
}
}
\me
\seealso{
\command{\link{RMmodel}},
\command{\link{RFsimulate}},
\command{\link{RFfit}}.
}
\keyword{spatial}
\keyword{models}
\examples{\dontshow{StartExample()}
RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set
## RFoptions(seed=NA) to make them all random again
model <- RMcircular()
x <- seq(0, 10, 0.02)
plot(model)
plot(RFsimulate(model, x=x))
\dontshow{FinalizeExample()}}
|
