[R-sig-Geo] How to convert esri shapefiles to ppp objetcs/ owin object

[Roger Bivand]

On Mon, 11 Sep 2006, Debarchana Ghosh wrote:

> 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