Hello! I believe I've found a bug in the type conversion process from polygon to point.
In the documentation found here http://www.postgresql.org/docs/9.2/interactive/functions-geometry.html, Table 9-32 claims that running the point() function on a polygon returns the "center of polygon". This is not the case for some polygons, as shown below. I'm running postgres 9.2.2, on Mac 10.8. This is a fresh install of Postgres.app from http://postgresapp.com/ : frink:~ cdunklau$ psql psql (9.2.2) Type "help" for help. For the below two queries, I expect to get a result of (0.5, 0.5). cdunklau=# select point( polygon '((0,0),(0,1),(1,1),(0,1))'); point ------------- (0.25,0.75) (1 row) cdunklau=# select point( polygon '((0,0),(1,0),(1,1),(1,0))'); point ------------- (0.75,0.25) (1 row) The conversion does indeed work as expected for other polygons: cdunklau=# select point( polygon '((-1,-1),(-1,1),(1,1),(1,-1))'); point ------- (0,0) (1 row) Please let me know if you have problems reproducing this error, or if I can assist in any way to isolate the problem. I had hoped to use the type conversion to replace center-finding application logic, but it appears I'll need to keep the application logic at least until this bug is fixed. Best regards, Colin Dunklau -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
