[R] maptools/spatial analysis question

[Roger Bivand]

Albert-Jan Roskam <fomcl <at> yahoo.com> writes:

> 
> Hi,
> 
> I am using maptools to plot air quality data on a map. Each measurement point
is mapped to a postal code area.
> This yields pictures with discrete borders, like so:
> http://dl.dropbox.com/u/27415200/baincome.png
> The problem is that the size of a postal code area doesn't mean much in this
context. Moreover, only a small
> minority of all the postal code areas has a measurement sation. Are there any
ways/tools to "interpolate"
> the various (strategically chosen) measurement stations? I am looking for
sensible ways to create plots
> like this:

Have you looked at the section on geostatistics and interpolation on the
"Spatial" task view on CRAN:

http://cran.r-project.org/web/views/Spatial.html

You may also find the R-sig-geo list more appropriate.

Hope this helps,

Roger

> 
> http://matplotlib.github.com/basemap/_images/etopo5.png
>