Dear Emanuele, Did you first checked manually the presence of anisotropy with gstat variogram function? Then consider also that automatic fitting procedure generally are not capable to fit a zonal anisotropy but only a geometric one.
Sebastiano Il sab 13 lug 2019, 07:32 Emanuele Barca <emanuele.ba...@ba.irsa.cnr.it> ha scritto: > 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 > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo