[R-sig-Geo] GWR with GWT file

[Roger Bivand]

On Thu, 11 Mar 2010, Jay Douillard wrote:

> I'm working on a project where the distance between two polygons may be 
> a poor measure of connectivity(contigious polygons that may have an 
> impassible mountain chain between them. To get a better measure of 
> distance I've used road network distances from population weighted 
> centroids of the polygons. I've created a row standarized gwt style file 
> using arcgis's network tools, and a bit of table editing. I can 
> successfully import this into R. File format in "old style GWT" for 
> example:

> 473
> 1 2 .111
> 1 3 .22
> 1 4 .66
> 2 1 .11
>
>
> Is possible to use your own weighting scheme in spgwr? Is it using a 
> listw object? I couldn't find any indication in the documentation.

Jay,

It isn't, but it probably wouldn't be too hard to do under certain 
conditions. The non-neighbours would be treated as outside the bandwidth, 
I suppose, otherwise one is looking at a full matrix for asymmetric road 
networks. The source for spgwr is on the r-spatial project on sourceforge, 
so you could check out what there is and see how one might add a listw= 
argument to gwr() for a given bandwidth first - branching around the 
spDistsN1() in .GWR_int() after passing the listw object through.

Roger

>
> thanks!
>
>
> ----
> Jay Douillard
> Geospatial Technical Lead
> 604.827.4401
> Human Early Learning Partnership
> www.earlylearning.ubc.ca
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no