[R-sig-Geo] spatial correlation structure in lme

[wudadan]

Dear R users,

I need some help in understanding the spatial correlation structure. Is
there a document or paper that explains how to use spatial correlation
structure such as "corExp"?

Here is the problem I run into. With the spatial correlation structure:

 "correlation = corExp(c(10,0.8),form = ~ north + east)"

 I tried to define the range and nugget as 10 miles and 0.8, respectively.
However, I got the error message "Error in initialize.corSpatial....Initial
value for corSpatial parameters of wrong dimension". Can anyone tell me what
this means?

I then tried the script:

"correlation = corExp(10,form = ~ north + east)"

It worked. However, it seems the range "10" was not used because after I
changed it to "3", I got exactly the same estimation results. I'm wondering
what the right way to do this.

Any advice is appreciated!

Best
Gary


 


 

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