Interactively choose smoothing parameter value

Description

An interactive function showing the fitted variogram and the mapping transformation from the geographical space into D-space, allowing the user to interactively choose a suitable value for the smoothing parameter ("lambda").

Usage

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Ftransdraw(disp, Gcrds, MDScrds, gridstr, sta.names, lambda = 0,
           lsq = FALSE, eye, model = 1, a0 = 0.1, t0 = 0.5)

Arguments

disp

n \times n dispersion matrix, equal to 2-2 (spatial correlation matrix)

Gcrds

n \ times 2 coordinate matrix (in G-space)

MDScrds

Coordinates of new locations – as calculated by Falternate3

gridstr

grid coordinates, obtained from Fmgrid using Gcrds as input

sta.names

names of locations; if not provided, locations will be numbered 1 to n

lambda

initial value of the smoothing parameter

lsq

logical flag used in Sampson-Guttorp method

eye

eye perspective; if not provided, locations will be selected using the provided data

model

type of variogram: 1 for exponential or 2 for gaussian

a0, t0

initial variogram parameter estimates

Value

A list containing the following named components:

Dcrds

n \times 2 cooridnate matrix of new locations in D-space

Ddist

n \times n matrix of interdistances in D-space

Note

The graphic device has to be setup before engaging this function, for example using the 'setplot' function:

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par(mfrow=c(1,2))
	temp <- setplot(coords.lamb, ax=TRUE)

In window, after entering the function call in R console, click on the graphical device to register the curse before proceeding and this interactive function will provide instructions for using a different smoothing parameter value; ie. enter a new lambda value in R console, then click on the graphical device to see results.