Hi there everyone, I've been messing about using the Google Directions API thing recently, and came across some odd results. Code to demonstrate is below.
Essentially the distance between two points using PostGIS is 18 metres, yet when I translate the points to Lat/Long and then stick them in the Google API the distance comes out as 1 metre. Does anyone have any thoughts on this? Thanks James -------------------------------------------------------------------- -- Calculate a distance between two points using SRID 27700 (OSGB36): SELECT St_Distance( St_SetSRID(ST_makePoint(531058, 178463), 27700) , St_SetSRID(ST_makePoint(531041, 178455), 27700) ) RESULT = 18.7882942280559 (I presume metres) --------------------------------------------------------------------- -- Now calculte a distance between two points using SRID 4326 (WGS84): SELECT St_Distance( St_Transform(St_SetSRID(ST_makePoint(531058, 178463), 27700), 4326), St_Transform(St_SetSRID(ST_makePoint(531041, 178455), 27700), 4326) ) RESULT = 0.000256838311729703 (I presume degrees) --------------------------------------------------------------------- -- Now calculate the distance using the Google Directions API using the Lat/Lon values: http://maps.googleapis.com/maps/api/directions/json?origin=51.4899343224464%20-0.113689479559085&destination=51.4898663658699%20-0.113937164484113&mode=walking&sensor=false&units=metric RESULT = "1 m" _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
