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<TITLE>Need help in using spdep package for running spatial models</TITLE>
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<P><FONT SIZE=2>Hi everyone,<BR>
<BR>
I am new to spatial modeling using R, and I will be grateful for any tip.<BR>
<BR>
I have an ArcGIS shapefile database of ~800 regions (consisting of ~5000 polygons) in geographic projection (lat-long). I have a response variable, Y, and 4 explanatory variables, X1, X2, X3 and X3. I hope to compare single-term GLMs (of X1, X2, X3 and X4 against the null model - on a normal distribution, controlling for spatial autocorrelation in all these models).<BR>
<BR>
>From reading the vignette and spdep package pdf, I understand that the spdep package enables me to carry out the analyses. But I am not sure which functions I should use - hope someone can guide me.<BR>
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Firstly, I intend to determine at which neighborhood distances, (and also whether neighborhood coding are weighted or binary) are spatial autocorrelation reduced to acceptable levels based on Moran's I.<BR>
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Secondly, I hope to generate a neighbor list/matrix based on the above-mentioned values. Are there any functions that allow me to do that? (many of the regions have consist of more than 1 polygon).<BR>
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Thirdly, using the neighbourhood list, run SAR (lagged, mixed and err) using "lagsarlm" and "errsarlm". Perform model selection as usual using AIC, wAIC and %DE.<BR>
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I would be really grateful, if anyone could comment on the suitability of my analytic framework, and point out certain functions I can use (especially for the first and second points).<BR>
<BR>
Thanks for reading this lengthy post.<BR>
<BR>
Best regards,<BR>
Xingli<BR>
<BR>
------------------------------------<BR>
Xingli Giam<BR>
Research Visitor<BR>
Research Institute of Climate Change and Sustainability<BR>
School of Earth and Environmental Sciences<BR>
The University of Adelaide<BR>
Mobile: +61 (0) 425 150 966<BR>
Email: xingli.giam@adelaide.edu.au<BR>
Alt email: giam@nus.edu.sg<BR>
<BR>
<BR>
and<BR>
<BR>
M.Sc. Candidate<BR>
Department of Biological Sciences<BR>
National University of Singapore<BR>
(on study leave till 30 June 2009)<BR>
<BR>
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