Variogram
Usage
vgram(loc, y, lon.lat=F)
Arguments
loc
|
Matrix where each row is the coordinates of an observed point of the field
|
y
|
Value of the field at locations
|
lon.lat
|
If true, locations are assumed to be longitudes and latitudes and
distances found are great circle distances. Default is false.
|
Value
Object of class vgram. This is list with components d the pairwise
distances
, vgram the value of the variogram and loc the locations.References
See any standard reference on spatial statistics. For example
Cressie Spatial StatisticsExamples
# compute variogram for the Chicago ozone field
vgram( ozone$x, ozone$y, lon.lat=T)-> out
plot( out$d, out$vgram, xlab="Distance", ylab="Squared differences")