R help - Dec 2011 - maptools/spatial analysis question

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:

http://matplotlib.github.com/basemap/_images/etopo5.png
> sessionInfo()
R version 2.11.1 (2010-05-31) 
i686-pc-linux-gnu 
...

 
Thank you in advance!


Cheers!!
Albert-Jan


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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
>