Mercurial > gemma
view schema/geo_functions.sql @ 3703:b07511ff859e
Don't include calculated area in unchanged bottleneck detection.
This makes BN imports considerably faster. The only downside is, that
when die waterway area changes there is no easy way to recalculate the
areas of existing BN. But the semantics in that case are somewhat
hard anyway (think of historization for the old area) so this should
be ok.
author | Sascha Wilde <wilde@intevation.de> |
---|---|
date | Wed, 19 Jun 2019 12:34:48 +0200 |
parents | eeeb7bf14217 |
children |
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-- This is Free Software under GNU Affero General Public License v >= 3.0 -- without warranty, see README.md and license for details. -- SPDX-License-Identifier: AGPL-3.0-or-later -- License-Filename: LICENSES/AGPL-3.0.txt -- Copyright (C) 2018, 2019 by via donau -- – Österreichische Wasserstraßen-Gesellschaft mbH -- Software engineering by Intevation GmbH -- Author(s): -- * Sascha L. Teichmann <sascha.teichmann@intevation.de> -- * Tom Gottfried <tom@intevation.de> CREATE OR REPLACE FUNCTION best_utm(g geography) RETURNS integer AS $$ DECLARE center geometry; BEGIN -- Centroid should be calculated on geography to get accurate results -- from lon/lat coordinates, but the respective PostGIS function returns -- POINT(-NaN NaN) for some invalid polygons, while the calculation on -- geometry seems to give reasonable approximations in this context. SELECT ST_Centroid(CAST(g AS geometry)) INTO center; RETURN CASE WHEN ST_Y(center) > 0 THEN 32600 ELSE 32700 END + floor((ST_X(center)+180)/6)::int + 1; END; $$ LANGUAGE plpgsql IMMUTABLE;