[R-sig-Geo] SDM and SDEM models with single aliased feature and lag

[Roger Bivand]

On Mon, 2 May 2022, Ari via R-sig-Geo wrote:

> Hello everyone,

> I am working with a SDM and SDEM models from the spatialreg package in a 
> geographical pattern containing some islands. While simulating the 
> regressions I encountered aliased variables, but to my surprise it only 
> reported a single feature (and its lag). In previous cases when I 
> encountered aliased variables it always was between a pair of features, 
> as it usually meant that they both had perfect collinearity. I know how 
> to adapt the data to deal with perfect colinearity, but I am not sure on 
> how to proceed if only one feature (and its lag) are reported as 
> aliased? Could it be caused by the "isolated nature" of the dataset 
> (despite working with the zero.policy=TRUE argument)?

Could you please provide reproducible examples of these cases, for example 
using the Boston data set ?spData::boston ? Please also report whether the 
variables are categorical (in R factors), or not. Without a minimal worked 
example, it isn't obvious what the problem might be. By feature, do you 
mean a single geometry/observation, or several observations on one 
subgraph?

Roger

>
> Thanks the help.
> Best regards,
> Ari
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-- 
Roger Bivand
Emeritus Professor
Department of Economics, Norwegian School of Economics,
Postboks 3490 Ytre Sandviken, 5045 Bergen, Norway.
e-mail: Roger.Bivand using nhh.no
https://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en