Roger,
> Without having tried your code, how similar is this to these packages:
>
> https://cran.r-project.org/package=micromap
> https://cran.r-project.org/package=micromapST
Thanks for responding. I looked at the micromap vignettes but it seems their
focus is being able to provide small maps in one column in figures where the
main emphasis is on statistics presented in other columns. In my problem, all
I want to show are maps. I haven't been able to do this with a higher-level
function like spplot or stplot. I can imagine doing it with a custom panel
function, where lpolygons() is used with input that depends on the panel.
In case it helps, I should clarify that the "different polygons" I referred to
are polygons with different spatial coordinates; the attribute values are a
small number of discrete values. My polygons are representations of
contaminant plumes in groundwater. For each year, I have read in a shapefile
containing polygons of the contaminant concentration at 2 to 4 levels. I have
combined all of these data into a SpatialPolygonsDataFrame, where each row
represents a given year and concentration level, and contains one or more
polygons. The coordinates are different in each row, but years and
concentration level are common across rows. This seems to match the nature of
a "long table" format in spacetime, but I haven't been able to work it out in
that package, hence I'm stepping back and trying to get the basics working with
spplot.
Thanks,
Scott
> > Hello,
> >
> > I have a SpatialPolygonsDataFrame. I would like to do a trellis plot on one
> of the attributes, so that in the panel for a given attribute value, only
> those
> polygons with that value are plotted. So, each panel has different polygons
> plotted in it. I can't figure out how to do this. In the toy example below,
> I
> would like to create a trellis plot with one panel showing the polygons with
> id
> = 1, and another panel showing the polygons with id = 2.
> >
> > My goal beyond this toy problem is to do the same thing with stplot, where
> panels correspond to times and each time has a different set of polygons
> plotted. Will that be possible? In all the examples I can find of using
> stplot
> for a space-time grid with the spatial objects being polygons, the polygons
> are the same across time.
> >
> > # based on example in help("SpatialPolygonsDataFrame-class")
> > Sr1 = Polygon(cbind(c(2,4,4,1,2),c(2,3,5,4,2)))
> > Sr2 = Polygon(cbind(c(5,4,2,5),c(2,3,2,2)))
> > Sr3 = Polygon(cbind(c(4,4,5,10,4),c(5,3,2,5,5)))
> > Sr4 = Polygon(cbind(c(5,6,6,5,5),c(4,4,3,3,4)), hole = TRUE)
> > Srs1 = Polygons(list(Sr1), "s1")
> > Srs2 = Polygons(list(Sr2), "s2")
> > Srs3 = Polygons(list(Sr3, Sr4), "s3/4") SpP =
> > SpatialPolygons(list(Srs1,Srs2,Srs3), 1:3) grd <- GridTopology(c(1,1),
> > c(1,1), c(10,10)) polys <- as(grd, "SpatialPolygons") centroids <-
> > coordinates(polys) x <- centroids[,1] y <- centroids[,2] z <- 1.4 +
> > 0.1*x + 0.2*y + 0.002*x*x id = factor(sample(c(1,2),
> > size=length(polys), replace=T)) tmp <- SpatialPolygonsDataFrame(polys,
> > data=data.frame(x=x, y=y, z=z, id=id,
> > row.names=row.names(polys)))
> > plot(tmp) # plots all the square polygons (n = 10*10)
> > spplot(tmp) # plots values of x, y, z, id in separate panels, each
> > with 100 polys spplot(tmp, zcol=z) # error message about duplication
> > of factor level spplot(tmp ~ id, zcol=z, data=tmp) # won't take
> > formula
> >
> > Thank you,
> > ScottWaichler
> > Pacific Northwest National Laboratory
> > scott.waichler _at_ pnnl.gov
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
>
> --
> Roger Bivand
> Department of Economics, Norwegian School of Economics, Helleveien 30, N-
> 5045 Bergen, Norway.
> voice: +47 55 95 93 55; e-mail: roger.biv...@nhh.no
> http://orcid.org/0000-0003-2392-6140
> https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
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