Thanks Mike... works.
On Mar 15, 2012, at 10:08 PM, Mike Toews wrote: > On 16 March 2012 15:47, Puneet Kishor <punk.k...@gmail.com> wrote: >> I am trying to create a simple 1 deg x 1 deg grid and transform it to >> spherical mercator >> >> SELECT ST_Transform(ST_MakeEnvelope(minx, miny, maxx, maxy, 4326), >> 900913) the_geom >> FROM ( >> SELECT lng minx, lat miny, (lng + 1) maxx, (lat + 1) maxy >> FROM ( >> SELECT Generate_series(-180, 180, 1) lng, >> Generate_series(-90, 90, 1) lat >> ) series >> WHERE (lng + 1) < 181 AND (lat + 1) < 91 >> ) lat_lng >> >> >> I get >> >> ERROR: transform: couldn't project point (-180 -90 0): tolerance >> condition error (-20) >> >> >> >> What am I doing wrong? > > Transform has difficulties at the poles, since the limits of math are > stretched. > > If you aren't gridding polar bears and/or penguins, then you should > use only latitudes from 79S to 79N. Try this: > > SELECT ST_Transform(ST_MakeEnvelope(minx, miny, maxx, maxy, 4326), > 900913) the_geom > FROM ( > SELECT lng minx, lat miny, (lng + 1) maxx, (lat + 1) maxy > FROM ( > SELECT Generate_series(-180, 179, 1) lng, Generate_series(-89, > 88, 1) lat > ) series > ORDER BY lng, lat > ) lat_lng; _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users