
304 Data Analysis and Statistics for Geography, Environmental Science, and Engineering
Package sgeostat’s theta angle convention is angle with respect to E and counter clockwise. So, NE
would be θ = 45, N would be θ = 90, NW would be θ = 135, SW would be θ = 225, S would be
θ=270, and SE would be θ = 315.
Generate pairs for NE direction with narrow tolerance of 7.5°
>maas45.v <- vario(maas,num.lags=10,type=‘anisotropic’, theta=45,
dtheta=7.5, maxdist=2000)
The variogram
> maas45.v
lags bins classic robust med n
1 1 99.95315 135180.0 68358.08 104208.72 31
2 2 299.85945 132956.6 88038.82 85371.46 72
3 3 499.76576 189284.1 101127.83 51681.92 104
4 4 699.67206 ...