After getting the data from Jaime offline, I got this working, following
Roger's suggestion.
Code is on cvs and will be in the next release.
--
Edzer
Roger Bivand wrote:
On Thu, 31 Jul 2008, Jaime Carrera wrote:
Hi,
I'm trying to create a spplot with a vector map on the background. It
works fine if I don't want the polygon map to be filled, but what I
do want to is to have the polygons filled with different colors. The
following command plots the polygon map fine, filling each polygon
with its respective color:
plot(avi,axes=FALSE,lty=0,col=rgb(avi$r/255,avi$g/255,avi$b/255))
Now I try to do this on ssplot, but it doesn't work, as all polygons
are filled with the first color found:
basemap<-list("sp.polygons",avi,fill=rgb(avi$r/255,avi$g/255,avi$b/255),lty=1)
spplot(wells2001sp,c("May","Jun"),as.table=TRUE,sp.layout=list(basemap))
Is there a way around it?
Not for spplot in the current code. The fill= argument in
"sp.polygons" is passed through to the internal function sp.polygon3
without being indexed, so grid.polygon gets given the whole fill
vector each time, and takes the first value. We can try to add the
functionality at some time in the future - or others could help - type
sp.polygons at the prompt to see the code. fill= is being passed in
the ... arguments, and needs to be conditioned on, and fill=fill[i]
passed to sp.polygon3.
The sp code is on the r-spatial sourceforge site - patches welcome!
Roger
PS: This is a first cut:
sp.polygons = function(obj, col = 1, fill="transparent", ...) {
sp.polygon3 = function(x, col, fill, ...) {
cc = slot(x, "coords")
grid.polygon(cc[,1], cc[,2], default.units = "native",
gp = gpar(col = col, fill = fill, ...))
panel.lines(cc, col = col, ...)
}
if (is.character(obj))
obj = get(obj)
if (!is(obj, "SpatialPolygons"))
stop(paste("object extending class SpatialPolygons",
"expected; got class", class(obj)))
else
obj = as(obj, "SpatialPolygons")
pls = slot(obj, "polygons")
pO <- slot(obj, "plotOrder")
if (length(fill) != length(pO)) fill <- rep(fill[1], length(pO))
for (i in pO) {
Srs <- slot(pls[[i]], "Polygons")
pOi <- slot(pls[[i]], "plotOrder")
for (j in pOi)
sp.polygon3(Srs[[j]], col = col, fill = fill[i], ...)
}
}
Thanks,
Jaime
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
--
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster,
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de/
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
