Ftransdraw: Interactively choose smoothing parameter value

In EnviroStat: Statistical Analysis of Environmental Space-Time Processes

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

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:

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.

EnviroStat documentation built on May 2, 2019, 2:32 p.m.