SimulateRF {RandomFields}R Documentation

Simulation of Random Fields

Description

DoSimulateRF performs an already initialised simulation.

InitSimulateRF internal function; use InitGaussRF and InitMaxStableRF, instead.

Usage

DoSimulateRF(n=1, register=0)

InitSimulateRF(x, y=NULL, z=NULL, T=NULL, grid, model, param, trend,
               method=NULL, register=0, gridtriple=FALSE, distribution=NA)

Arguments

x matrix of coordinates, or vector of x coordinates
y vector of y coordinates
z vector of z coordinates
T time instances
grid logical; determines whether the vectors x, y, and z should be interpreted as a grid definition, see Details.
model string; covariance or variogram model, see CovarianceFct, or type PrintModelList() to get all options
param vector or list. param=c(mean, variance, nugget, scale, ...), param=list(c(variance, scale, ...), ..., c(variance,scale,...)), param=matrix(...), or param=list(list(variance, anisotropy, kappa),..., list(variance, anisotropy, kappa)); the parameters must be given in this order; further parameters are to be added in case of a parametrised class of models, see CovarianceFct
trend Not programmed yet. trend surface: number (mean), vector of length d+1 (linear trend a_0 +a_1 x_1 + ... + a_d x_d), or function
method NULL or string; Method used for simulating, see RFMethods, or type PrintMethodList() to get all options
n number of realisations to generate
register 0:9; place where intermediate calculations are stored; the numbers are aliases for 10 internal registers
gridtriple logical; if gridtriple==FALSE ascending sequences for the parameters x, y, and z are expected; if gridtriple==TRUE triples of form c(start,end,step) expected; this parameter is used only if grid==TRUE
distribution marginal distribution:
'Gauss', 'Poisson', or 'MaxStable'.

Value

InitSimulateRF returns 0 if no error has occurred during the initialisation process, and a positive value if failed.

DoSimulateRF returns NULL if an error has occurred; otherwise the returned object depends on the parameters n and grid:
n==1:
* grid==FALSE. A vector of simulated values is returned (independent of the dimension of the random field)
* grid==TRUE. An array of the dimension of the random field is returned.

n>1:
* grid==FALSE. A matrix is returned. The columns contain the repetitions.
* grid==TRUE. An array of dimension d+1, where d is the dimension of the random field, is returned. The last dimension contains the repetitions.

Author(s)

Martin Schlather, martin.schlather@cu.lu http://www.cu.lu/~schlathe

See Also

GaussRF, MaxStableRF, RandomFields


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