That's right, we don't have a way to differentiate between great-circle
edges and loxodromes on geography (or vice versa in geometry).
You can approximate a "square" by densifying your east-west lines in the
places you want vertices to go, but the inter-vertex edges will still be
great circles.
Thanks Paul, I get it now.
So I guess, it all comes from the fact that an arc is defined as the
shortest path between 2 points which in the geometry case is a straight
line and in the geography case is a great circle.
This also mean that "the polygon I had in mind" cannot be defined as a
geography
Thanks for your reply Paul.
Yes, that's what I thought. That would explain why (0,-82) is inside the
polygon.
Nevertheless, if my first segment runs through the south pole, then I would
expect both of the queries mentioned in my initial post to return 0 which
is not the case.
Sebastien
On Mon,
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
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.
