I'm having trouble understanding the angles reported from the Variogram Map. Here is an example of one I created:
modelvm <-
vmap.auto(vm,
flag.noreduce = TRUE,
lower = c("M1V1=0.2"),
upper = c("M1V1=0.5"),
struct = melem.name(c(1, 2, 3)))
I added the "lower" and "upper" arguments to be consistent with my model created earlier. The image I am uploading is the result. Intuitively, the max direction of continuity seems correct. The "spike" may be an indication of a fault (?) (it seems to offset the principle ellipse). But I'm trying to identify what the Exponential component is that has an angle of 16.4 degrees. The principal contribution seems to come from the Spherical model (~ -160 degrees, although I am not sure why it reports it as a -160 degrees.
Here are the stats that came back:
Covariance Part
---------------
Nugget Effect
- Sill = 0.200
Exponential
- Sill = 2.127
- Ranges = 561.358 14983.560
- Theo. Ranges = 187.386 5001.636
- Angles = 16.444 0.000 <- HOW DO I INTERPRET THIS? I know this is a smaller structure, but is this something which I simply cannot see (too small)? Rotation Matrix
[, 0] [, 1]
[ 0,] 0.959 -0.283
[ 1,] 0.283 0.959
Spherical
- Sill = 2.922
- Ranges = 57706.480 17955.536
- Angles = -159.860 0.000 <- HOW TO INTERPRET THIS? This is consistent with the Max dir of continuity. Why the "-" sign, why not just +20 degrees???
- Rotation Matrix
[, 0] [, 1]
[ 0,] -0.939 0.344
[ 1,] -0.344 -0.939
Total Sill = 5.249
Drift Part