spatial (version 7.3-5)

expcov: Spatial Covariance Functions

Description

Spatial covariance functions for use with surf.gls.

Usage

expcov(r, d, alpha = 0, se = 1)
gaucov(r, d, alpha = 0, se = 1)
sphercov(r, d, alpha = 0, se = 1, D = 2)

Arguments

r

vector of distances at which to evaluate the covariance

d

range parameter

alpha

proportion of nugget effect

se

standard deviation at distance zero

D

dimension of spheres.

Value

• vector of covariance values.

References

Ripley, B. D. (1981) Spatial Statistics. Wiley. Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

See Also

surf.gls

Examples

data(topo, package="MASS")
topo.kr <- surf.ls(2, topo)
correlogram(topo.kr, 25)
d <- seq(0, 7, 0.1)
lines(d, expcov(d, 0.7))