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: [EMAIL PROTECTED] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo