I don't the polygon you've draw means what you think it does. POLYGON((-90 -80, 90 -80, 90 10, -90 10, -90 -80))
For example, you probably figure the first segment, -90 -80, 90 -80 runs east-west between two points close to the south pole. In fact, it runs directly over the south pole, so actually to the south of your point of interest. P On Sun, Feb 19, 2017 at 7:36 PM, Sebastien Delaux <[email protected]> wrote: > Hi all, > > I am new to postgis and I am interested in finding all the points that are > located at x metres or less of a polygon that are stored in my postgres > database. > As I am working with data located all over the world and want to work with > distances in metres I decided to use the geography type. > > I am trying to understand why the following query returns 0 when the point > is clearly not included in the polygon: > SELECT ST_Distance(ST_GeographyFromText('SRID=4326;POINT(0. > -82.)'),ST_GeographyFromText('SRID=4326;POLYGON((-90 -80, 90 -80, 90 10, > -90 10, -90 -80))')); > > I suspect this has something to do with the polygon crossing the equator > as > SELECT ST_Distance(ST_GeographyFromText('SRID=4326;POINT(0. > -82.)'),ST_GeographyFromText('SRID=4326;POLYGON((-90 -80, 90 -80, 90 -10, > -90 -10, -90 -80))')); > returns a plausible distance. > > Would anybody know whether my polygon is violating some assumption or > whether there is any other reason that I am getting those results? > > Thanks > > Sebastien > > > > > > > > _______________________________________________ > postgis-users mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/postgis-users >
_______________________________________________ postgis-users mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/postgis-users
