Hi, i used upgis_lineshift function, it works but not as well as needed. I prepared map, where you can see result. The problem is, that it is not perpendicular and when used in different directions with same distance function parameter, the distance is different. Point 1,2 is original and 3,4 result of function, point 5,6 original and 7,8 result.
http://maps.google.com/maps/api/staticmap?center=na%20zborenci,Praha&zoom=18&size=1024x1024&maptype=roadmap&; markers=color:red|label:1|50.07698059082031,14.416675567626953&markers=color:red|label:2|50.07749938964844,14.41646957397461 &markers=color:red|label:3|50.0770728490573,14.4169079217053&markers=color:red|label:4|50.0775916478854,14.4167019280529 &markers=color:blue|label:5|50.07719802856445,14.417106628417969&markers=color:blue|label:6|50.077693939208984,14.418004989624023 &markers=color:blue|label:7|50.0769791612592,14.417227446888&markers=color:blue|color:blue|label:8|50.0774750719037,14.418125808094&sensor=false I used query like select ST_AsText(upgis_lineshift( ST_GeomFromText('LINESTRING(14.416675567626953 50.07698059082031, 14.41646957397461 50.07749938964844)', 4326) , 0.00025)) Do you know, where is problem? I guess, it is connected with projection but no idea how to correct it. May be, concerning angles the method works well and when looking on the result placed on geoid, it is ok. But I do not understand, why the distance is too much different. Thanks, Ota Charles Galpin-2 wrote: > > Check out the upgis_lineshift function on > > http://trac.osgeo.org/postgis/wiki/UsersWikiplpgsqlfunctions > > The resulting line will have endpoints that you want. > > hth > charles > > On Apr 29, 2010, at 7:10 PM, ots wrote: > >> >> Hello, >> I have oriented line. The line is given as two points (WGS84). I need to >> calculate coordinates(also WGS84) of next two points on one side (left or >> right) of the line in the given distance so all 4 points make together >> rectangle. >> Is there some function that can help me? I was searching but no idea. >> > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > -- View this message in context: http://old.nabble.com/Calculate-coordinates-tp28405927p28414891.html Sent from the PostGIS - User mailing list archive at Nabble.com. _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
