spVariofit: Fit a variogram model

In lrcastro/spANOVA: Spatial Analysis of Field Trials Experiments using Geostatistics and Spatial Autoregressive Model

Description

Fit a parametric model to a variogram created by the function spVariog.

Usage

spVariofit(x, ...)

Arguments

x	an object of class spVariog.
...	further arguments to be passed to variofit function.

Details

This function is a wrapper to variofit and can be used to fit a parametric model to a variogram using either ordinary least squares or weighted least squares. It takes as the main argument a spVariog object and others arguments should be passed to ... such as "cov.model" and so on.

Value

an object of class SpVariofit which is a list containing the following components:

mod	an object of class variofit
data.geo	an object of class geodata
des.mat	the design matrix
trend	a character specifying the type of spatial trend

See Also

variofit

Examples

data("crd_simulated")
dados <- crd_simulated

#Geodata object
geodados <- as.geodata(dados, coords.col = 1:2, data.col = 3,
                      covar.col = 4)
h_max <- summary(geodados)[[3]][[2]]
dist <- 0.6*h_max

# Computing the variogram
variograma <- spVariog(geodata = geodados,
                      trend = "cte", max.dist = dist, design = "crd",
                      scale = FALSE)

plot(variograma, ylab = "Semivariance", xlab = "Distance")

# Spherical Model
ols1 <- spVariofit(variograma, cov.model = "spherical", weights = "equal",
                  max.dist = dist)
lines(ols1)

lrcastro/spANOVA documentation built on Aug. 21, 2019, 11:45 a.m.