variogram range is not unique within some specific degree

Question

variogram of the dataset

I got this variogram from a set of spatial temporal data, but i am wondering why the 90 degree have such a 'small' range compare to other, is it my data problem or I can adjust some setting in the

v<-variogram(Thickness~Age+x+y,data,alpha=seq(0,135,45),beta=seq(0,45,45))

Any suggestion? Thank you

Answer 1

I will assume that you are referring to the range of the plotted graph and not the range parameter that is used in Geostatistics.

This is simply, because the longest distance is smaller at 90 degrees. For example, imagine that you have observations in a rectangle with width 100 and height 50. Then, when computing the variagrom, pair of points will be observed at the distance of at most 100 for 0 degrees, while, at most of 50 for 90 degrees.