Message-ID: <A632B3F93D861843A3C966F3962C3F8401080DD39972@EMAIL05.pnl.gov>
Date: 2010-08-11T04:47:46Z
From: Waichler, Scott R
Subject: Directional variograms with 3D data
Hello,
I have a dataset with coordinates in x, y, z. I would like to generate directional variograms, including ones for distinct horizontal and vertical directions, and fit models to them. Apparently geoR does not accept 3D coordinates, so I am left with (?) gstat. I have trouble understanding and applying the 5-parameter version of anis in gstat's vgm(), so I thought I would try generating one direction at a time, as below with a data frame called "han":
th.vg1 <- variogram(th ~ 1, han, alpha=0, tol.hor = 90, beta=0, tol.vert=30) # within 30 deg of horizontal
th.vg2 <- variogram(th ~ 1, han, alpha=0, tol.hor = 90, beta=90, tol.vert=30) # within 30 deg of vertical
th.vg1 and th.vg2 are identical; both are omnidirectional. What do I need to do to to get distinct horizontal and vertical directions?
Scott Waichler
Pacific Northwest National Laboratory
P.O. Box 999, Richland, WA 99352
scott.waichler at pnl.gov
509-372-4423, 509-341-4051 (cell)