[R-sig-Geo] plot.polylist polygon plot order

2007-07-18 Thread Jeff Jorgensen
Hi Bob, Thanks for the suggestion. I figured out a way to force the polygon plot order, by referencing one of the attributes of the imported shapefile. The polygons I used were 6th field HUCs and I was able to use this attribute to order plotting: shape<-readShapePoly(shapefile)#shapefile has

Re: [R-sig-Geo] plot.polylist polygon plot order

2007-07-18 Thread Sutherland, Robert D (DFG)
Hi Jeff, This is what I did. HistBreaks<-quantile(datafileDf$nhunters,probs=c(0.1,0.2, 0.4,0.6,0.8,0.9,1.0),na.rm=TRUE) np<-findInterval(datafileDf$nhunters, histBreaks, all.inside=TRUE) colorsToUse<-colorSchemeV5 plot.polylist(datafilePolys, col=colorsToUse[np], forcefill=FALSE) plot.polylist(d

[R-sig-Geo] plot.polylist polygon plot order

2007-07-18 Thread Jeff Jorgensen
Hello, I've imported a shapefile of polygons (R v2.5.1 winxp, maptools v0.6-13) and I'm trying to assign colors to polygons in plot.polylist(). Is there a way to force the order in which polygons are plotted get the correct color associations to the corresponding polygons? Best regards, Jeff

Re: [R-sig-Geo] The sum.w Field in SDF

2007-07-18 Thread Roger Bivand
On Wed, 18 Jul 2007, Ryan Rosario wrote: > I understand that the sum.w field is the sum of the weights associated with > a particular observation/location. This is apparently a follow-up to a question on 15 July about robust GWR. GWR is seriously affected by multicollinearity anyway (see Wheeler

[R-sig-Geo] Group-wise error variance and autocorrelation

2007-07-18 Thread Tim Keitt
I'm trying to specify a model where the fixed effects are dep ~ group + group:indep and the error variance and spatial autocorrelation vary by group. I've tried lme but AFAICT it only supports heteroscedasticity and autocorrelation within groups. Any pointers? THK -- Timothy H. Keitt, Universi

Re: [R-sig-Geo] Non-symmetric variogram map in gstat

2007-07-18 Thread David Rossiter
Edzer Pebesma wrote: > David, you may also notice that the map produced does not have a cell > centre or cell 'crossing' at (0,0). Of course you'd assume enough > cleverness that this would be enforced automatically, but too bad. Try > > v <- variogram(Ni ~ 1, jura.pred, cutoff=1.8, width=0.18,

Re: [R-sig-Geo] Non-symmetric variogram map in gstat

2007-07-18 Thread Edzer J. Pebesma
David, you may also notice that the map produced does not have a cell centre or cell 'crossing' at (0,0). Of course you'd assume enough cleverness that this would be enforced automatically, but too bad. Try v <- variogram(Ni ~ 1, jura.pred, cutoff=1.8, width=0.18, map=T) (making sure that the

[R-sig-Geo] The sum.w Field in SDF

2007-07-18 Thread Ryan Rosario
I understand that the sum.w field is the sum of the weights associated with a particular observation/location. But what is this sum taken over? Is there a way to access the individual weights before they are summed? Basically, I need a single weight for each observation (not a sum), so that I can

[R-sig-Geo] Non-symmetric variogram map in gstat

2007-07-18 Thread David Rossiter
I've found a quite puzzling behaviour in gstat's variogram method, with the map=T argument. I believe the result should be a symmetric map because all the semivariances are squared differences. This is indeed the case if I try an example from the Meuse set: > library(gstat) > data(meuse) > coordin