Falternate3: Simultaneous coordinate and variogram estimation
In EnviroStat: Statistical Analysis of Environmental Space-Time Processes

Description Usage Arguments Details Value Warning Note

Perform simultaneous estimation of coords and exponential or gaussian variogram by alternating weighted least squares.

Falternate3(disp, coords, model = 1, a0 = 0.1, t0 = 0.5,
            max.iter = 50, max.fcal = 100, alter.lim = 50,
            tol = 1e-05, prt = 0, dims = 2, lambda = 0,
            ncoords, dev.mon = NULL, verbose = FALSE)

`disp`	n \times n dispersion matrix, equal to 2 - 2 (spatial correlation matrix)
`coords`	n \times 2 coordinate matrix
`model`	type of variogram: 1 for exponential or 2 for gaussian
`a0, t0`	initial variogram parameter estimates
`max.iter, max.fcal`	control parameter for calls to non-linear optimization routines (same values used in MDS step and in variogram step)
`alter.lim`	maximum number of iterations of pairs of alternating calls to `Fmdsfit3` (coordinate estimation) and `Fvariogfit3` (variogram fitting)
`tol`	convergence criterion for coordinate estimates
`prt`	not used
`dims`	dimension of multi-dimensional scaling
`lambda`	smoothing parameter
`ncoords`	n \times 2 optional initial coordinates to use if not G-plane
`dev.mon`	Function to open the graphics device used for plots monitoring the convergence of objective. If `NULL`, monitoring plots will not be created.
`verbose`	if `TRUE`, display the results of each iteration to the console

This version permits dimension > 2 for scaling. In the plotting we'll use a plot symbol proportional to the third coordinate.

A list containing the following named components:

`variogfit`	Fitted variogram parameters with new locations
`ncoords`	n\times 2 matrix with coordinates of new locations

make sure that coords are scaled reasonably small before attempting to compute; otherwise matrix inversion is likely not to work in calculation of bending energy matrix.

This version also passes a smoothing parameter to the optimization. This parameter probably is not scaled exactly the same as it is in sinterp and this has not been investigated yet.

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