R: Variogram Model Similar to Fractal Brownian Motion
RMflatpower
R Documentation
Variogram Model Similar to Fractal Brownian Motion
Description
RMflatpower is an intrinsically stationary isotropic variogram
model. The corresponding centered semi-variogram only depends on the
distance r ≥ 0 between two points and is given by
γ(r) = r^2 / ( 1 + r^2)^α
where 0 < α ≤ 1.
For related models see RMgenfbm.
Usage
RMflatpower(alpha, var, scale, Aniso, proj)
Arguments
alpha
numeric in (0,1]; refers to the fractal dimension of the
process
var,scale,Aniso,proj
optional arguments; same meaning for any
RMmodel. If not passed, the above
variogram remains unmodified.
Details
The model is always smooth at the origin.
The parameter α only gives the tail behaviour and
satisfies 0
< α ≤ 1.
The variogram is unbounded and belongs to a non-stationary process with
stationary increments.
Oesting, M., Schlather, M., and Friederichs, P. (2014)
Conditional Modelling of Extreme Wind Gusts
by Bivariate Brown-Resnick Processes
arxiv1312.4584.
See Also
RMgenfbm,
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
model <- RMflatpower(alpha=0.5)
x <- seq(0, 10, 0.1)
plot(model)
plot(RFsimulate(model, x=x))
Results
R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
> library(RandomFields)
Loading required package: sp
Loading required package: RandomFieldsUtils
This is RandomFieldsUtils Version: 0.2.1
This is RandomFields Version: 3.1.16
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
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/RandomFields/RMoesting.Rd_%03d_medium.png", width=480, height=480)
> ### Name: RMflatpower
> ### Title: Variogram Model Similar to Fractal Brownian Motion
> ### Aliases: RMflatpower
> ### Keywords: spatial models
>
> ### ** Examples
>
> RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set
> ## RFoptions(seed=NA) to make them all random again
>
> model <- RMflatpower(alpha=0.5)
> x <- seq(0, 10, 0.1)
> plot(model)
NULL
> plot(RFsimulate(model, x=x))
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)'.
> ## Don't show:
> FinalizeExample()
> ## End(Don't show)
>
>
>
>
>
> dev.off()
null device
1
>