How to convert esri shapefiles to ppp objetcs/ owin object

Hi All,

I'm in the process of conducting spatial point clustering where the
locations are very important by using splancs and spatstat packages. However
it looks like I'm stuck at the very first step. Even after reading the
manuals, I can't figure it out how to create the ppp class object from the
esri shapefiles specially the uneven polygon. I have a study area of seven
counties. Any help on this will greatly appreciated.

Please have a look at the functions in the spspatstat package on 
sourceforge - http://r-spatial.sourceforge.net/ and see download for 
download instructions. If the sp package is installed first:

rSpatial <- "http://r-spatial.sourceforge.net/R"
install.packages("spspatstat", repos=rSpatial)

should work (unless OSX when type="source" is also needed). That lets you 
convert points and windows from sp class objects. See the R News note on 
sp classes in 2005/2, pp. 9-13.

If you can see additions to the interface package that would be useful, 
please let us know.

Roger

Thanks,
Debs.

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 at nhh.no