AI-GEOSTATS: Interpretation of rho and its control in Splus
- Dear List members,
What would be a good interpretation for the coefficient Rho in a conditional autoregressive (CAR) model?
I have looked through the literature (Cressie and such) but haven't found a good verbal interpretation. Is it fair to say that the larger rho, the stronger the spatial effect.
Also, does someone on this list know how to control rho in Splus? I would like to force it to 0 occasionally to get a "null" model for Rsquare and AIC calculations.
Dept. of Wildlife Ecology - Rm. 210
University of Maine
5755 Nutting Hall
Tel: (207) 581 2799
Fax: (207) 581 2858
[Non-text portions of this message have been removed]
- On Thu, 16 Oct 2003, Volker Bahn wrote:
> Dear List members,Yes and no. Larger absolute values would indicate stronger spatial
> What would be a good interpretation for the coefficient Rho in a
> conditional autoregressive (CAR) model? I have looked through the
> literature (Cressie and such) but haven't found a good verbal
> interpretation. Is it fair to say that the larger rho, the stronger the
> spatial effect.
effects, larger positive values stronger positive spatial autocorrelation
reducing the effective number of observations. Robert Haining's new book
on "Spatial Data Analysis" is a good source on these kinds of questions
(2003, Cambridge UP).
>Perhaps just fit lm(), AIC should be OK, as should the likelihood ratio
> Also, does someone on this list know how to control rho in Splus? I
> would like to force it to 0 occasionally to get a "null" model for
> Rsquare and AIC calculations.
test. I don't have access to the software, so I'm generalising from how
similar classes work in R.
> Thank you--
> Volker Bahn
> Dept. of Wildlife Ecology - Rm. 210
> University of Maine
> 5755 Nutting Hall
> Orono, Maine
> 04469-5755, USA
> Tel: (207) 581 2799
> Fax: (207) 581 2858
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
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