[R-sig-Geo] Problem reading in polygon shapefile with readShapePoly

[Steven J. Pierce]

Roger,

That worked. I successfully read in the file and plotted the resulting
parcels object. Onward with my dissertation work! Thanks for responding so
rapidly and for generously sharing your time and expertise. 


Steven J. Pierce
Center for Statistical Training & Consulting (CSTAT)
Michigan State University
Web: http://www.cstat.msu.edu


-----Original Message-----
From: Roger Bivand [mailto:Roger.Bivand at nhh.no] 
Sent: Monday, June 22, 2009 1:29 PM
To: Steven J. Pierce
Subject: RE: [R-sig-Geo] Problem reading in polygon shapefile with
readShapePoly

On Mon, 22 Jun 2009, Steven J. Pierce wrote:

> Roger,
>
> I posted a zip file containing that set of shapefiles at 
> [link removed]. Thank you 
> so much for taking a look at this.

Steven,

Please try this draft package:

http://spatial.nhh.no/R/Devel/maptools_0.7-25.zip

It worked for me on your example file. The tests inside readShapePoly were
for ring closure using all.equal(), which permits a very small amount of
machine fuzz, but in the Polygon class are identical(); this in addition to
changes made after the reports about June 10. I've imposed identical() in
both places, so the forcing policy now also forces ring closure on rings
that were closed within machine precision, but not bit-identical first and
last coordinates.

Please let me know if this resolves your problem, if so, I'll release.

Best wishes,

Roger

--
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