[R-sig-Geo] Considering "boundary effect" in spdep or spgwr

[Hisaji ONO]

Thank you very much for you kind advice.


--- Roger Bivand <Roger.Bivand at nhh.no> wrote:

> On Thu, 28 Sep 2006, Hisaji ONO wrote:
> 
> > Hello.
> > 
> >  In some "geo-spatial analysis" text books &
> articles,
> > "boundary effect" was referred.
> > 
> >  For spatial weight matrix and its related
> statistical
> > methods, this issue is very important, I think.
> > 
> >  For this issue, I've looked for this in "spdep"
> and
> > "spgwr" in their "manual" pdf files, but no luck.
> > 
> >  Current version of these packages consider
> "boundary
> > effect"? 
> > 
> 
> Yes, you are right that boundary (or edge) effects
> can be important. They 
> concern the extent to which inferences may change if
> we change the edges 
> of the study area, and/or the configuration effect
> that occurs when some 
> observations are fully surrounded (in the centre of
> the study area) and 
> others are on the edge. 
> 
> There is an indirect reference to this in the
> joincount.test() example in
> spdep - it uses different settings of the spatial
> weights style= argument
> to show how weights configuration can change
> inference. So in spdep, the
> only treatment is through the style= argument.
> 
> In spgwr, fitting adaptive bandwidths seems to be
> one way of preventing
> observations far from their neighbours being
> impacted by a single global
> distance bandwidth. The GWR book doesn't have edge
> effects in its index.
> 
> Best wishes,
> 
> Roger
> 
> > 
> > 
> >  Regards.
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> -- 
> 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
> 
>