-----Original Message----- >From: Roger Bivand <[EMAIL PROTECTED]> >Sent: Mar 16, 2008 4:42 AM >To: [EMAIL PROTECTED] >Cc: r-sig-geo@stat.math.ethz.ch >Subject: Re: [R-sig-Geo] writing shapefiles using write.pointShape > >On Thu, 13 Mar 2008, [EMAIL PROTECTED] wrote: > >> I'm also having issues with getting the gw.cov function to work for fit >> points. Here's an example, using the same files... >> >>> pcavars <- names(surveypts[,4:8]) >>> pcavars >> [1] "pca1" "PCA2" "PCA3" "PCA4" "PCA5" >>> surv.cov <- gw.cov(data = surveypts, vars = pcavars, fit.points = fitpix, >>> bw = survey.bw) >> Error in gw.cov(surveypts, test, fit.points = fitpix, bw = survey.bw) : >> unused argument(s) (fit.points = <S4 object of class "SpatialPixels">) >> >> As far as I can tell, I'm using the same syntax as in the ggwr function. >> Thanks again. =) > >?gw.cov will help. The first argument is x= not data=, and fit.points= >should be fp=. So > >surv.cov <- gw.cov(x=surveypts, vars=pcavars, fp=fitpix, bw=survey.bw) > >ought to work. The functions are fairly different (no formula=), so >assuming that the arguments have the same names suggests that actually >reading the help pages might save time.
Yep, tunnel vision as I said before. I actually do read those help pages, believe it or not. Many times. Finding the difference between calling fp= and fit.points= for the same file is actually easy to overlook. > >Please note that spgwr is only a proof of concept package and does not >imply any affirmation of approaches using geographical weights. The >approach may be helpful, but following Wheeler and Tiefelsdorf (2005), >caution is recommended. Your use of PCAs may help alleviate the induced >collinearity in GWR regression coefficients, but please always plot >pairs() of the local coefficients! Thanks Roger, I'll do that. I'm actually evaluating several modelling approaches for large geographic prediction surfaces, and non-stationarity appears to be a very large issue (among others). I wanted to see how gwr compared to some of the other methodologies, and it appeared R was the only way I could evaluate it without having to buy a license. So, yes. You have a newbie in R on board. _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo