Mercurial > gemma
changeset 3589:033366f94abf
Added a geometry version of best_utm() for convenience.
| author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
|---|---|
| date | Tue, 04 Jun 2019 12:29:20 +0200 |
| parents | cffa99aa523c |
| children | 309084558808 |
| files | schema/geo_functions.sql |
| diffstat | 1 files changed, 16 insertions(+), 6 deletions(-) [+] |
line wrap: on
line diff
--- a/schema/geo_functions.sql Tue Jun 04 12:12:30 2019 +0200 +++ b/schema/geo_functions.sql Tue Jun 04 12:29:20 2019 +0200 @@ -12,16 +12,12 @@ -- * Sascha L. Teichmann <sascha.teichmann@intevation.de> -- * Tom Gottfried <tom@intevation.de> -CREATE OR REPLACE FUNCTION best_utm(g geography) RETURNS integer AS +CREATE OR REPLACE FUNCTION best_utm(g geometry) RETURNS integer AS $$ DECLARE center geometry; BEGIN - -- Centroid should be calculated on geography to get accurate results - -- from lon/lat coordinates, but the respective PostGIS function returns - -- POINT(-NaN NaN) for some invalid polygons, while the calculation on - -- geometry seems to give reasonable approximations in this context. - SELECT ST_Centroid(CAST(g AS geometry)) INTO center; + SELECT ST_Centroid(g) INTO center; RETURN CASE WHEN ST_Y(center) > 0 THEN @@ -33,3 +29,17 @@ $$ LANGUAGE plpgsql IMMUTABLE; + +CREATE OR REPLACE FUNCTION best_utm(g geography) RETURNS integer AS +$$ +BEGIN + -- Centroid should be calculated on geography to get accurate results + -- from lon/lat coordinates, but the respective PostGIS function returns + -- POINT(-NaN NaN) for some invalid polygons, while the calculation on + -- geometry seems to give reasonable approximations in this context. + RETURN best_utm(CAST(g as geometry)); +END; +$$ +LANGUAGE plpgsql +IMMUTABLE; +