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Given Paul Ramsey's excellent explanation of why the next question is what can be done about it. How do you SELECT DISTINCT on geometry fields and have it perform as expected? In Paul's answer, I proposed using SELECT MAX(geom) FROM the_table GROUP BY ST_AsBinary(geom); but MAX() is slow, apparently requiring a table scan. Instead, I found this to be ...


Finding the center is not as simple as you think. take an example square in EPSG:4326: Transform it into World Mercator, and the center is somewhere else: In Lambert conformal conical, it is not yet a rectangle: And same for azimutal equidistant: So be careful if you think of a "simple" rectangle and its center point. The world is not a plane! My ...


Vincenty's formula (ellipsoid based) is more accurate than haversine (sphere based). Also, lat and long are usually expressed in degree, but your coordinates are not in 0-180, therefore you could be in another system than expected.


It needs to be set in the "layerOptions" parameter. This parameter takes a list of strings of the format "OPTION=VALUE", corresponding to OGR layer options for the vector format. So, for coordinate precision, try setting this parameter to: ['COORDINATE_PRECISION=3'] (or whatever your desired precision is). Additional valid parameters are listed on the OGR ...

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