RMnsst: Non-Separable Space-Time model
In RandomFields: Simulation and Analysis of Random Fields

Description Usage Arguments Details Value References See Also Examples

RMnsst is a univariate stationary spaceisotropic covariance model whose corresponding covariance is given by

C(h,u)= (ψ(u)+1)^{-δ/2} φ(h /√(ψ(u) +1))

1	RMnsst(phi, psi, delta, var, scale, Aniso, proj)

`phi`	is a normal mixture `RMmodel`, cf. `RFgetModelNames(monotone="normal mixture")`
`psi`	is a variogram `RMmodel`.
`delta`	a numerical value; must be greater than or equal to the spatial dimension of the field.
`var,scale,Aniso,proj`	optional arguments; same meaning for any `RMmodel`. If not passed, the above covariance function remains unmodified.

This model is used for space-time modelling where the spatial component is isotropic.

RMnsst returns an object of class RMmodel.

Gneiting, T. (1997) Normal scale mixtures and dual probability densitites, J. Stat. Comput. Simul. 59, 375-384.
Gneiting, T. (2002) Nonseparable, stationary covariance functions for space-time data, JASA 97, 590-600.
Gneiting, T. and Schlather, M. (2001) Space-time covariance models. In El-Shaarawi, A.H. and Piegorsch, W.W.: The Encyclopedia of Environmetrics. Chichester: Wiley.
Schlather, M. (2010) On some covariance models based on normal scale mixtures. Bernoulli, 16, 780-797.

RMgennsst, RMmodel, RFsimulate, RFfit.

RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set
##                   RFoptions(seed=NA) to make them all random again

model <- RMnsst(phi=RMgauss(), psi=RMfbm(alpha=1), delta=2)
x <- seq(0, 10, 0.25)
plot(model, dim=2)
plot(RFsimulate(model, x=x, y=x))

Loading required package: sp
Loading required package: RandomFieldsUtils

Attaching package: 'RandomFields'

The following object is masked from 'package:RandomFieldsUtils':

    RFoptions

The following objects are masked from 'package:base':

    abs, acosh, asin, asinh, atan, atan2, atanh, cos, cosh, exp, expm1,
    floor, gamma, lgamma, log, log1p, log2, logb, max, min, round, sin,
    sinh, sqrt, tan, tanh, trunc

NULL
NOTE: simulation is performed with fixed random seed 0.
Set 'RFoptions(seed=NA)' to make the seed arbitrary.
New output format of RFsimulate: S4 object of class 'RFsp';
for a bare, but faster array format use 'RFoptions(spConform=FALSE)'.