Re: bubble vs plot.map -- gstat, maptools

On Thu, 11 May 2006, Zev Ross wrote:

> Hi All,
> 
> I've got another question for the group. I'm using the bubble function in
> GSTAT to plot the residuals from a krige.cv object. I'd like to place on
> top the outlines of my counties of interest (or even better I'd like to
> plot them in the reverse order). What I'm finding is that even if I
> eliminate the key and eliminate the "asp" call from the bubble function,
> my two plots don't align as they do under more traditional plotting
> circumstances
> 
> Here's the idea:
> 
> kcv28<-krige.cv(avg.pm25~1,pm.all28, vFitRaw, nmax=dim(pm.all28)[1],
>      nfold=dim(pm.all28)[1])
> bubble(kcv28, "residual", do.sqrt=F)
> map.nyc<-read.shape("D:/junk/counties/all_counties.shp", dbf.data=T)
> plot(map.nyc, add=T, fg="transparent", ol="gray50")

Well, bubble() uses lattice graphics, and the plot() methods are most 
often base graphics:

library(maptools)
xx <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1])
xx$crude <- (1000*xx$SID74)/xx$BIR74
out <- bubble(pts, "crude")
plot(xx, axes=TRUE)
symbols(out$panel.args[[1]], circles=out$panel.args.common$cex/10, 
  bg=out$panel.args.common$col, inches=FALSE, add=TRUE)

is pretty close (with a kludgy cex/10 size factor), or

plot(xx, axes=TRUE)
points(out$panel.args[[1]], cex=out$panel.args.common$cex, 
  col=out$panel.args.common$col, pch=out$panel.args.common$pch)

using points(). See

str(out)

to pick out the guts of the bubble lattice plot object. The plot() 
method used here, symbols() and points() are all in base grahics.

Also see a recent paper in JSS by Susumu Tanimura, Chusi Kuroiwa, and 
Tsutomu Mizota, including some legend code:

http://www.jstatsoft.org/

Volume 15, 2006, Issue 5 

Roger

> 
> Any suggestions? Zev
> 
> --
> Zev Ross
> ZevRoss Spatial Analysis
> 303 Fairmount Ave
> Ithaca, NY 14850
> (607) 277-0004 (phone)
> (866) 877-3690 (fax toll-free)
> zev@xxxxxxxxxxx
> www.zevross.com
> 
> 

-- 
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@xxxxxx