[R-sig-Geo] anisotropic models vs. detrending

[Kerry Ritter]

Hi. I was wondering which model you would tend to choose given similar 
cross validation results. 
1. An isotropic model with linear trend
2. An anisotropic model
Assume linear trend is ~x + y + I(x*y), where x,y are spatial coordinates.

I have read papers that argue that unless you know how to interpret the 
linear trend (from a phyiscal/geographical/biological point of view) it 
is better NOT to detrend the data prior to fitting a variogram.  On the 
other hand, one must ultimately assume stationarity. So I am not sure 
which way to go.  How do you decide?

Thanks,
Kerry

-- 
**********************
Kerry Ritter, Ph.D.
statistician
Southern California Coastal Water Research Project
3535 Harbor Blvd., Suite 110

work: 714-755-3210
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email: kerryr at sccwrp.org