vgm {gstat}R Documentation

Generate, or Add to Variogram Model

Description

Generates a variogram model, or adds to an existing model. print.variogram.model prints the essence of a variogram model.

Usage

vgm(psill, model, range, nugget, add.to, anis, kappa = 0.5)
print.variogram.model(x, ...)

Arguments

psill (partial) sill of the variogram model component
model model type, e.g. "Exp", "Sph", "Gau", "Mat". Calling vgm() without a model argument returns the list with available models.
range range of the variogram model component
kappa smoothness parameter for the Matern class of variogram models
nugget nugget component of the variogram (this basically adds a nugget compontent to the model)
add.to a variogram model to which we want to add a component
anis anisotropy parameters:
x a variogram model to print
... arguments that will be passed to print, e.g. digits (see examples)

Value

an object of class variogram.model, which extends data.frame Calling vgm without a model argument returns the list with available models.

Author(s)

Edzer J. Pebesma

References

See Also

print.variogram.model, fit.variogram, variogram.line, variogram for the sample variogram.

Examples

vgm(10, "Exp", 300)
x <- vgm(10, "Exp", 300)
vgm(10, "Nug", 0)
vgm(10, "Exp", 300, 4.5)
vgm(10, "Mat", 300, 4.5, kappa = 0.7)
vgm( 5, "Exp", 300, add.to = vgm(5, "Exp", 60, nugget = 2.5))
vgm(10, "Exp", 300, anis = c(30, 0.5))
vgm(10, "Exp", 300, anis = c(30, 10, 0, 0.5, 0.3))
# Matern variogram model:
vgm(1, "Mat", 1, kappa=.3)
x <- vgm(0.39527463, "Sph", 953.8942, nugget = 0.06105141)
x
print(x, digits = 3);
# to see all components, do
print.data.frame(x)

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