[postgis-users] ST_Intersects on geography

[Kidd, David M]

Hi,

Applogies if the is a stupid newbie question.

I have am writing some some simple point in polygon searches on geographic data using ST_Intersects, but have been getting some unexpected results;

Searching for a point in the southern hemisphere:

SELECT ST_Intersects('POINT(-160 -43)'::geography, 'POLYGON((-180 -90, -180 0, 180 0, 180 -90, -180 -90))'::geography)

Returns f

Searching for a point in the northern hemisphere:

SELECT ST_Intersects('POINT(160 43)'::geography, 'POLYGON((0 0, 0 90, 180 90, 180 0, 0 0))'::geography)

ERROR:  BOOM! Could not generate outside point!
CONTEXT:  SQL function "st_intersects" statement 1

********** Error **********

ERROR: BOOM! Could not generate outside point!
SQL state: XX000
Context: SQL function "st_intersects" statement 1
This works though






David M. Kidd

Research Associate
Center for Population Biology
Silwood Park Campus
Imperial College London
0207 594 2470


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