An object of class variogram contains empirical variogram estimates generated from a point object and a pair object. A
variogram object is stored as a data frame containing six columns: lags, bins, classic, robust, med, and n. The length of each
vector is equal to the number of lags in the pair object used to create the variogram object, say l. The lags vector contains the
lag numbers for each lag, beginning with one (1) and going to the number of lags (l). The bins vector contains the spatial midpoint
of each lag. The classic, robust, and med vectors contain the classical,
variogram estimates for each lag, respectively (see Cressie, 1993, p. 75).
The n vector contains the number |N(h)| of pairs of points in each lag N(h).
Usage
est.variogram(point.obj, pair.obj, a1, a2)
Arguments
point.obj
a point object generated by point()
pair.obj
a pair object generated by pair()
a1
a variable to calculate semivariogram for
a2
an optional variable name, if entered cross variograms will be created between a1 and a2
Value
A variogram object:
lags
vector of lag identifiers
bins
vector of midpoints of each lag
classic
vector of classic variogram estimates for each lag