spatio-temporal

Dear all.
I am trying to calculate and 3d plot of empirical spatio-temporal
variogram using RandomFields
and CompRandFld packages. The below program is an example in
CompRandFld package:


library(CompRandFld)
library(RandomFields)
library(scatterplot3d)
set.seed(31231)
# Define the spatial-coordinates of the points:
x <- runif(20, 0, 1)
y <- runif(20, 0, 1)
# Define the temporal sequence:
time <- seq(0, 50, 1)
# Simulation of the spatio-temporal Gaussian random field:
data <- RFsim(x, y, time, corrmodel="exp_exp",param=list(mean=mean,
nugget=nugget,scale_s=0.5,scale_t=1,sill=sill))$data

the error is :

Error: could not find function "RFsim"

please guide me about this.
Thanks.

Saman Monfared
Msc Student,
Department of Statistics, Shiraz University,
Shiraz 71454, Iran
Email: Samanmonfared1 at gmail.com

Tel: +98 917 5305167