> Thanks for your response. However, this is also not giving the answer I > expect. As the input you show illustrates, this input gives a response of 45 > degrees, whereas the answer should be 90 degrees if 90 90 corresponds to the > north pole and 0 0 a point on the equator. I have also tried this with a > point 89 89 with a similar problem. A point 90 0 does however give the > correct result of 90 degrees. Do I still have the wrong idea about what the > function should do? >
One important PostGIS feature is that the computations are done in a planar, cartesian system. Geodetic coordinates are not understood by postgis (except with the *_sphere() or *_spheroid() functions) We (at camptocamp) are currently leading a survey to estimate the effort needed to integrate a geodetic support in Postgis, like Oracle spatial does. So the given result is correct to a planar point of vue, but wrong if you consider coordinates on the earth surface. Nicolas _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
