This function is generic; method functions can be written to handle specific classes of objects. Classes which already have methods for this function include
default,
gls, and
lme. See the appropriate method documentation for a description of the arguments.
USAGE:
Variogram(object, distance, ...)
VALUE:
depends on the method function used; see the appropriate documentation.
REFERENCES:
Cressie, N.A.C. (1993). Statistics for Spatial Data. New York: J. Wiley & Sons.