R: Semivariance Values For a Given Variogram Model

variogramLine {gstat} | R Documentation

## 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))

[Package gstat version 2.0-3 Index]