ShowModels {RandomFields}R Documentation

Interactive Choice of Models and Parameters

Description

ShowModels is an interactive plot for the selection of models and their one- or two-dimensional simulations; it also allows for the fitting of variogram models by eye.

CURRENTLY NOT AVAIABLE IN VERSION 2 OF RANDOMFIELDS. PLEASE USE VERSION 1.3.47 INSTEAD.

Usage

ShowModels(x, y=NULL,
           covx=ifelse(is.null(empirical), diff(range(x))/5,
                       max(empirical$c)), 
           fixed.rs=TRUE, method=NULL, empirical=NULL,
           model=NULL, param=NULL, anisotropy = FALSE, all.param=NULL,  
           legends = TRUE, 
           register=0, Mean=NULL, erase=TRUE,
           x.fraction=0.60, cex.names=1, covx.default = 100,
           link.fct=NULL, Zlim=NULL,
           Col.rect="red", Col.bg="blue", Col.sep="grey",
           Col.line="red", Col.txt="black", Col.flash="red",
           Col.vario="blue", Col.main="black",
           Col.model=c("red", "black"),  vario.lty=c(1,2), 
           cex.leg = 0.7 * cex.names,  cex.eval = 0.8 * cex.names,
           update=TRUE, screen.new=TRUE, use.outer.RFparameters=FALSE,
           debug=FALSE, ...)

Arguments

x

if NULL simulations are not performed; otherwise it gives the x coordinates of a grid as a sequence of increasing numbers

y

if NULL at most one-dimensional simulations are performed (depending on the value of x); otherwise y gives the y coordinates of a two-dimensional grid (as a sequence of increasing numbers).

covx

if a single value is given, it is the largest distance for which the covariance functions or the variograms are plotted; otherwise the models are plotted for the given values, and the origin.

fixed.rs

if TRUE then the same random seed is used for all simulations until the user clicks on the formula, the title or the subtitles.

method

simulation method, see RFMethods; if NULL then a suitable simulation method is chosen automatically.

empirical

empirical variogram; a list as returned by EmpiricalVariogram. Also empirical variograms with a pair number of anisotropy directions may be passed. Then the first and the middle one are taken.

model

covariance model, see CovarianceFct, or type PrintModelList() to get all options. If given, this model is shown at the beginning. Additive or multiplicative models are not allowed.

However, model can also be given by a simple list definition, see CovarianceFct. Then param must not be given. In this case also anisotropic models can be defined.

param

parameter vector: param=c(mean, variance, nugget, scale,...); the parameters must be given in this order; see CovarianceFct for more details. Only considered if model is given. If given, model is initialised by param.

anisotropy

logical. If TRUE then an isotropic model is considered.

all.param

all.param=c(mean, variance, nugget, scale); the parameters must be given in this order; If all.param is given then the parameters of all covariance functions are set to the given values. The values are overwritten for a specific model if model and param are given. Note that it is not possible to set the values of additional (form) parameters of a parametrised class by means of all.param.

In case of an anisotropic model the anisotropy matrix is by default diagonal with both entries equal to 1/\code{all.param[4]}.

legends

if TRUE then a legend is added to the two-dimensional plot.

register

register where intermediate results of the simulations are stored, see also GaussRF.

Mean

mean of the random field

erase

parameter of split.screen, which is called at the very beginning

x.fraction

the current screen is split into 2 x 2 screens. The parameter x.fraction gives the size of the left screens in the x directions as part of 1. See also the Details.

cex.names

font size for model names

covx.default

if length(cov.x)==1 then [0, \code{cov.x}] is covered by covx.default points of equal distance

link.fct

NULL or function(values) or "MaxStable". Transformation of the Gaussian random field.

If link.fct="MaxStable" then max-stable random fields are simulated for the given covariance function and the extremal coefficient function is given (up the constant -1) instead of the variogram or the covariance function

Zlim

Vector of two elements or list of two vectors of two elements. Graphical limits for the Gaussian random process (and the transformed field).

Col.rect

colour for interactive plot; see eval.parameters.

Col.bg

colour for interactive plot; see eval.parameters.

Col.sep

colour for interactive plot; see eval.parameters.

Col.line

colour for interactive plot; see eval.parameters.

Col.txt

colour for interactive plot; see eval.parameters.

Col.flash

colour for the previously chosen model

Col.vario

colour for the empirical variogram plot

Col.main

colour for the title of the random field

Col.model

vector of two colours for plotting the variogram of the Gaussian random field and the transformed field

vario.lty

vector of two line types for primary and secondary axis of the variogram

cex.leg

font size used in the legends

cex.eval

font size used in the menue entries

update

logical. If TRUE the plots are updated after each interactive change of the values. Otherwise, the bottom 'simulate' is added in the menu.

screen.new

logical. If FALSE the screen is erased before a simulation and completely rebuild; otherwise the screen is updated. If FALSE flickering appears during the update of the current screen, otherwise it may happen during the reorganisation of any window (and may take quite a lot of time).

use.outer.RFparameters

logical. If FALSE the following parameters usually set by RFparameters are internally set

  • PracticalRange=FALSE

  • PrintLevel=1 if debug=FALSE and 5 otherwise.

  • maxstable.maxGauss=2

  • CE.force=TRUE

  • CE.trials=1

  • CE.mmin=-4

  • CE.useprimes=TRUE

debug

logical. If TRUE then internally the RFparameter()$PrintLevel is set to 5.

...

additional graphics options for the plot of the one- or two-dimensional simulations, see plot and image.

Details

The interactive plot consists of 3 parts:

The interactive plot is left by clicking any mouse button different from the left when the top right part is active.

Value

list of the last model and its parameters.

Author(s)

Martin Schlather, martin.schlather@math.uni-goettingen.de http://www.stochastik.math.uni-goettingen.de/~schlather

See Also

CovarianceFct, eval.parameters, GaussRF, RFMethods, RandomFields.

Examples

## Not run: 


# first example: one-dimensional simulations


# library(RandomFields)

options(locatorBell=FALSE)
x <-  seq(1,10,0.1)
ShowModels(x=x, covx=10, cov.def=100, type="l")


x <-  seq(1,10,0.1)
ShowModels(x=x, y=x, covx=10, cov.def=100)


# second example: two-dimensional simulations and
#                 empirical variogram
dx <- runif(300,0,8)
dy <- runif(300,0,8)
dz <- GaussRF(x=dx, y=dy, grid=FALSE, model="gaus",
      param=c(1,2,1,2))
ev <- EmpiricalVariogram(x=dx, y=dy, data=dz, grid=FALSE,
      bin=(-1:20)/4)
x <-  seq(1,5,0.1);
ShowModels(x=x, y=x, empirical=ev)

# third example: two-dimensional anistropic simulations and
#                link function

x <- seq(1,10,0.1)
ShowModels(x=x, y=x, link=function(x) exp(x),
          model=list(list(model="spheric", var=1, aniso=c(1,0,0,5))))

x <-  seq(1,10,0.1)
ShowModels(x=x, link=function(x) exp(x),
           model=list(list(model="spheric",var=1, scale=1)))



x <-  seq(1,10,0.1)
ShowModels(x=x, link="MaxStable", fixed.rs=TRUE,
           model=list(list(model="gauss",var=1, scale=1)), type="l")

## End(Not run) 


[Package RandomFields version 2.0.54 Index]