[R] Linking R to GIS

[Roger Bivand]

On Tue, 26 Jun 2001, Gatehouse, Simon (DEM, North Ryde) wrote:

> Dear All,
> Has anyone worked with linking R to both ArcView and MapInfo GIS systems? My
> desire is to capture object selection from GIS and pass to R and to return
> spatially based statistical model results from R to GIS. If both could
> simultaneously access the same data file this would be a bonus.
> 
> My inclination is to put together some routines based on ODBC linking but
> thought I would seek like minded people before 
> pressing too far into the evaluation.  Any thoughts or suggested alternative
> directions or shared examination would be welcome.
> 
One general comment and a couple of suggestions. Both ArcView and MapInfo
treat the geometry of spatial objects in a simplifying way, not handling
topology in the thorough way that heavy-duty GIS - like Arc-Info - do.
While most scientists are afforded access to desk-top style GIS such as
these, there are valid issues to be addressed about the need for topology
in interfacing (not least unambiguity in choice of spatial objects). The S
map.builder (http://lib.stat.cmu.edu/general/map.builder) does construct
the topology, GRASS does too, both for legacy vector and the forthcoming
5.1 beta vector revision.

Not forgetting that, your idea of doing the selection in the GIS and
getting R to interface the attribute table (ie. doing aspatial analysis on
the attributes in R) via ODBC is potentially viable. It might be feasible
to prototype it using the connections interface family now in R-base - see
the R Data Import/Export manual. Even writing a *.csv file might do - or
maybe the DCOM package under contrib/extra/dcom at CRAN. However, this
just gets the attribute data into R and back again.

I'm sure there are plenty of people with similar problems who would be
interested in how you progress.

Roger

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no
and: Department of Geography and Regional Development, University of
Gdansk, al. Mar. J. Pilsudskiego 46, PL-81 378 Gdynia, Poland.

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