RandomFields (version 3.0.32)

RMnonstwm: RMnonstwm

Description

RMnonstwm is a covariance model whose corresponding covariance $C$ is given by $$C(x, y)=\Gamma(\mu) \Gamma(\nu(x))^{-1/2} \Gamma(\nu(y))^{-1/2} W_{\mu} (|x-y|)$$ where $\mu = [\nu(x) + \nu(y)]/2$ and $W_{\mu}$ is the covariance of the RMwhittle model and $\nu$ is a positive function or a constant.

Usage

RMnonstwm(nu, var, scale, Aniso, proj)

Arguments

nu

positive argument defining the smoothness of the random field, or it is an arbitrary shape function.

var,scale,Aniso,proj

optional arguments; same meaning for any RMmodel. If not passed, the above covariance function remains unmodified.

Value

• RMnonstwm returns an object of class RMmodel

References

• Stein, M. (2005) Nonstationary Spatial Covariance Functions. Tech. Rep., 2005

See Also

RMwhittle, RMmodel, RFsimulate, RFfit.

Examples

RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set
##                   RFoptions(seed=NA) to make them all random again
\dontrun{
x <- seq(-1.2, 1.2, len=if (interactive()) 70 else 3)
model <- RMnonstwm(nu=RMgauss())z <- RFsimulate(model=model, x, x, grid=TRUE, n=4)
plot(z)
}
FinalizeExample()