variogramLine: Semivariance Values For a Given Variogram Model

In gstat: Spatial and Spatio-Temporal Geostatistical Modelling, Prediction and Simulation

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))

Example output

       dist    gamma
1   0.00001 5.000005
2   1.11112 5.525807
3   2.22223 5.996316
4   3.33334 6.417346
5   4.44445 6.794100
6   5.55556 7.131234
7   6.66667 7.432915
8   7.77778 7.702871
9   8.88889 7.944439
10 10.00000 8.160603
       dist     gamma
1   0.00001 0.0000030
2   1.11112 0.3278489
3   2.22223 0.6227728
4   3.33334 0.8518530
5   4.44445 0.9821677
6   5.55556 1.0000000
7   6.66667 1.0000000
8   7.77778 1.0000000
9   8.88889 1.0000000
10 10.00000 1.0000000
       dist     gamma
1   0.00001 0.0000015
2   1.11112 0.1659821
3   2.22223 0.3278475
4   3.33334 0.4814824
5   4.44445 0.6227716
6   5.55556 0.7475999
7   6.66667 0.8518521
8   7.77778 0.9314130
9   8.88889 0.9821674
10 10.00000 1.0000000
  dist     gamma
1  0.5 0.0749375
  dist     gamma
1 0.00 0.0000000
2 0.50 0.0749375
3 0.75 0.1122891

gstat documentation built on May 2, 2019, 4:59 p.m.