vgram {funfits}R Documentation

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 Statistics

Examples

# 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")


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