error in readShapePoly

Hi Roger,

Here is the result of the traceback():

4: .shp2srsI(shapes[[belongs[[i]][j]]],
.nParts.shpI(shapes[[belongs[[i]][j]]]),
      force_ring = force_ring)
3: .asSpatialPolygonsShapes(Map$Shapes, IDs, proj4string =

      force_ring = force_ring)
2: .Map2PolyDF(Map, IDs = IDvar, proj4string = proj4string, force_ring

force_ring,
      delete_null_obj = delete_null_obj, retrieve_ABS_null =
retrieve_ABS_null)
1:

geMaps\\NatureServe3.0\\",
      as.character(families[f]), "\\", as.character(spp.list[s2,
          1]), sep = ""), proj4string = CRS("+proj=latlong
+datum=NAD83"))

The shapefiles are bird range maps available online from NatureServe
here: http://www.natureserve.org/getData/birdMaps.jsp. The problem

is trin_inca_pl.shp which is included in the zipped 'Scolopacidae'

on that page.

Unfortunately, I am unfamiliar with the syntax of readOGR() and can't
quite figure out how I'm supposed to use it to read in a shapefile.

trin_inca_pl <- readOGR("Scolopacidae", "trin_inca_pl")

trin_inca_pl <- readShapePoly("Scolopacidae/trin_inca_pl.shp", 

Thanks!
Allen

-----Original Message-----
From: Roger Bivand [mailto:Roger.Bivand at nhh.no]
Sent: Wednesday, June 10, 2009 9:38 AM
To: Hurlbert, Allen H. (Biology)
Cc: r-sig-geo at stat.math.ethz.ch
Subject: Re: [R-sig-Geo] error in readShapePoly

On Wed, 10 Jun 2009, Hurlbert, Allen H. (Biology) wrote:

Hello list,



I'm new to GIS in R, so I appreciate any pointers with my problem.



I have code that uses readShapePoly to read in shapefiles in a loop

and

does some basic operations. This code appeared to be working great

twenty or so files, but then on one shapefile bonked with the

following

error:   Error in from[j]:to[j] : NA/NaN argument.



The problem shapefile opens fine in ArcGIS and there is nothing

readily

different about its attribute table or source information that I can

see

(and furthermore, all shapefiles are from the same standardized

source,

although of course that doesn't mean one of them didn't get messed up
somewhere along the way). I am running 2.7.2 on Windows XP x64.

Could you 1) try readOGR() in rgdal instead of readShapePoly() in
maptools
if possible, and see if the problem is repeated; 2) post either the
output
of traceback() run immediately after the error occurs (will show

more or less, the problem is in code) here and/or the shapefile(s) all
3-4
files in a zip archive on a website and post the URL here so that

can debug this? The problem seems to be a shot Pstart vector putting

invalid value into the range from which to extract ring coordinates,

the question is why it is shot.

If you can say something about the origin of the file, this may also
help
(what software wrote it), some have broken *.shx files.

Roger

Thanks in advance,

Allen


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