RMpower: Power operator for Variograms and Covariance functions
In RandomFields: Simulation and Analysis of Random Fields

Description Usage Arguments Details Value References See Also Examples

RMpower yields a variogram or covariance model from a given variogram or covariance model. The variogram gamma of the model is given by

gamma=phi^alpha

if phi is a variogram model. The covariance C of the model is given by

C(h) = phi(0)-(phi(0)-phi(h))^alpha

if phi is a covariance model.

1	RMpower(phi, alpha, var, scale, Aniso, proj)

`phi`	a valid `RMmodel`; either a variogram model or a covariance model
`alpha`	a numerical value in the interval [0,1]
`var,scale,Aniso,proj`	optional arguments; same meaning for any `RMmodel`. If not passed, the above covariance function remains unmodified.

If γ is a variogram, then γ^α is a valid variogram for α in the interval [0,1].

RMpower returns an object of class RMmodel.

Schlather, M. (2012) Construction of covariance functions and unconditional simulation of random fields. In Porcu, E., Montero, J. M., Schlather, M. Advances and Challenges in Space-time Modelling of Natural Events, Springer, New York.

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 <- RMpower(RMgauss(), alpha=0.5)
x <- seq(0, 10, 0.02)
plot(model)
plot(RFsimulate(model, x=x))