Fvariogfit3: Fit an exponential or gaussian variogram

In EnviroStat: Statistical Analysis of Environmental Space-Time Processes

Description

Fit an exponential or gaussian variogram with interdistances and corresponding dispersion values.

Usage

Fvariogfit3(disp.lt, h.lt, model = 1, a0 = 0.1, t0 = 0.5,
            max.iter = 25, max.fcal = 100, bep = 0, verbose = FALSE)

Arguments

disp.lt	vector of spatial dispersion values between locations (one value for each pair)
h.lt	vector of corresponding interdistances
model	type of variogram: 1 for exponential or 2 for gaussian
a0, t0	initial variogram parameter estimates
max.iter, max.fcal	control parameters for calls to non-linear optimization routines
bep	bending energy penalty, described in Sampson-Guttorp method (JASA 1992)
verbose	if TRUE, display fitting details to the console

Details

Exponential variogram is defined as a_1 + (2-a_1) (1-exp(-t_0 h)). Gaussian variogram is defined as a_1 + (2-a_1) (1-exp(-t_0 h^2)).

Value

A list containing the following named components:

objf	sum of residual sum of squares, plus bending energy penalty
a, t0	fitted parameters
fit	fitted values of variogram

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