Dear friends,
I have a dataset of hydraulic heads, mydata = <X, Y, HH, Z> and i would
like to check for anisotropy.
In R I found 3 functions to carry out such task:
1. likfit
x_geodata <- as.geodata(mydata, coord.cols = 1:2, data.col = 3,
covar.col = 4)
fit_mle <- likfit(x_geodata,
fix.nugget = FALSE,
cov.model = "exponential", psiA = 0, psiR = 1,
ini = c(var(Y), 1), fix.psiA = FALSE, fix.psiR =
FALSE,
hessian = TRUE)
that detects no anisotropy.
2. estimateAnisotropy
mydata.sp <- mydata
coordinates(mydata.sp) = ~ X + Y
estimateAnisotropy(mydata.sp, depVar = "LivStat", "LivStat ~ Z")
that returns the following
[generalized least squares trend estimation]
$`ratio`
[1] 1.340775
$direction
[1] -35.29765
$Q
Q11 Q22 Q12
[1,] 1.926136e-05 2.329241e-05 5.721893e-06
$doRotation
[1] TRUE
finally,
3. estiStAni
vmod1 <- fit.variogram(vgm1, vgm(18, "Ste", 1300, 0.78, kappa = 1.7))
estiStAni(vgm1, c(10, 150), "vgm", vmod1)
that returns an error:
Error in `$<-.data.frame`(`*tmp*`, "dir.hor", value = 0) :
replacement has 1 row, data has 0.
I am very puzzled, can anyone help me understanding if there is
anisotropy in my dataset?
thanks
emanuele