I had to build a rather complex fixing script as the problems are quite varied. Some could be fixed with a simple st_buffer(geom,0) while others required more advanced cleaning. Below is an incomplete list of problems I found while sorting through the data:
- Figure eights or as I like to call them, Loop-di-dos |><| - Self-Intersections at river heads due to the rather simplistic boundary simplification algorithms used. - Boundaries that back tracked along themselves. - Boundaries that contained a line off the boundary that represented a peninsula or pier that had zero area. - Overlapping borders that had to be cleaned for my data set so that no single point could belong in two countries. - There were also a few inconsistencies with naming conventions that had to be manually corrected based upon some research (thank you wikipedia). - Missing state/province and/or county/muncipality borders that left a few holes at the sub-country level in a few areas. - Some of my missing data and inconsistencies may have been corrected since I pulled the data a year or so ago. I'd offer to send you my cleaned up data set but unfortunately it has been updated with some proprietary data for Canada and Mexico. -- Nathan Gerber On Thu, Dec 30, 2010 at 7:03 PM, David Blackman <da...@whizziwig.com> wrote: > Hi all-- > > I'm trying to import the 10m-admin-1 data from > http://www.naturalearthdata.com/ to postgis 1.5.2. It's generating a > lot of invalid geometry that I don't know how to fix. > > My import command looks like this: > > shp2pgsql -W LATIN1 -I 10m-admin-1-states-provinces-shp > > 10m-admin-1-states-provinces-shp.sql > (note, in postgis2, this entirely fails on invalid input characters, > none of the character sets I tried worked) > > and of the import, 148 rows have invalid geometry, with errors like: > blackmad=# select fips_1 FROM > public."10m-admin-1-states-provinces-shp" WHERE ST_IsValid(the_geom) = > false; > NOTICE: Holes are nested at or near point 101.662 3.04074 > NOTICE: Self-intersection at or near point 120.185 22.9625 > NOTICE: IllegalArgumentException: Invalid number of points in > LinearRing found 2 - must be 0 or >= 4 > NOTICE: Ring Self-intersection at or near point -47.3025 -16.0401 > NOTICE: Too few points in geometry component at or near point -65.458 > -22.1012 > > This cleangeometry.sql script @ > http://www.sogis1.so.ch/sogis/dl/postgis/cleanGeometry.sql fixes most, > but the LinearRing errors cause the script to choke. > > Can someone advise me on how to fix these errors, or where the problem > lies (in the data or the import tool)? > > thanks > --dave > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users >
_______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
