variogramLine {gstat}

Semivariance Values For a Given Variogram Model

Description

Generates a semivariance values given a variogram model

Usage

variogramLine(object, maxdist, n = 200, min = 1.0e-6 * maxdist, 
	dir = c(1,0,0), covariance = FALSE, ..., dist_vector, debug.level = 0)

Arguments

object

variogram model for which we want semivariance function values

maxdist

maximum distance for which we want semivariance values

n

number of points

min

minimum distance; a value slightly larger than zero is usually used to avoid the discontinuity at distance zero if a nugget component is present

dir

direction vector: unit length vector pointing the direction in x (East-West), y (North-South) and z (Up-Down)

covariance

logical; if TRUE return covariance values, otherwise return semivariance values

...

ignored

dist_vector

numeric vector or matrix with distance values

debug.level

gstat internal debug level

Value

a data frame of dimension (n x 2), with columns distance and gamma (semivariances or covariances), or in case dist_vector is a matrix, a conforming matrix with semivariance/covariance values is returned.

Note

variogramLine is used to generate data for plotting a variogram model.

Author(s)

Edzer Pebesma

See Also

plot.gstatVariogram

Examples

variogramLine(vgm(5, "Exp", 10, 5), 10, 10)
# anisotropic variogram, plotted in E-W direction:
variogramLine(vgm(1, "Sph", 10, anis=c(0,0.5)), 10, 10)
# anisotropic variogram, plotted in N-S direction:
variogramLine(vgm(1, "Sph", 10, anis=c(0,0.5)), 10, 10, dir=c(0,1,0))
variogramLine(vgm(1, "Sph", 10, anis=c(0,0.5)), dir=c(0,1,0), dist_vector = 0.5)
variogramLine(vgm(1, "Sph", 10, anis=c(0,0.5)), dir=c(0,1,0), dist_vector = c(0, 0.5, 0.75))