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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
commit | 46651ce6fe013220ed397add242004d764fc0153 (patch) | |
tree | 6e5299f990f88e60174a1d3ae6e48eedd2688b2b /contrib/earthdistance/earthdistance--1.1.sql | |
parent | Initial commit. (diff) | |
download | postgresql-14-upstream.tar.xz postgresql-14-upstream.zip |
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'contrib/earthdistance/earthdistance--1.1.sql')
-rw-r--r-- | contrib/earthdistance/earthdistance--1.1.sql | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/contrib/earthdistance/earthdistance--1.1.sql b/contrib/earthdistance/earthdistance--1.1.sql new file mode 100644 index 0000000..9ef20ab --- /dev/null +++ b/contrib/earthdistance/earthdistance--1.1.sql @@ -0,0 +1,98 @@ +/* contrib/earthdistance/earthdistance--1.1.sql */ + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION earthdistance" to load this file. \quit + +-- earth() returns the radius of the earth in meters. This is the only +-- place you need to change things for the cube base distance functions +-- in order to use different units (or a better value for the Earth's radius). + +CREATE FUNCTION earth() RETURNS float8 +LANGUAGE SQL IMMUTABLE PARALLEL SAFE +AS 'SELECT ''6378168''::float8'; + +-- Astronomers may want to change the earth function so that distances will be +-- returned in degrees. To do this comment out the above definition and +-- uncomment the one below. Note that doing this will break the regression +-- tests. +-- +-- CREATE FUNCTION earth() RETURNS float8 +-- LANGUAGE SQL IMMUTABLE +-- AS 'SELECT 180/pi()'; + +-- Define domain for locations on the surface of the earth using a cube +-- datatype with constraints. cube provides 3D indexing. +-- The cube is restricted to be a point, no more than 3 dimensions +-- (for less than 3 dimensions 0 is assumed for the missing coordinates) +-- and that the point must be very near the surface of the sphere +-- centered about the origin with the radius of the earth. + +CREATE DOMAIN earth AS cube + CONSTRAINT not_point check(cube_is_point(value)) + CONSTRAINT not_3d check(cube_dim(value) <= 3) + CONSTRAINT on_surface check(abs(cube_distance(value, '(0)'::cube) / + earth() - '1'::float8) < '10e-7'::float8); + +CREATE FUNCTION sec_to_gc(float8) +RETURNS float8 +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT CASE WHEN $1 < 0 THEN 0::float8 WHEN $1/(2*earth()) > 1 THEN pi()*earth() ELSE 2*earth()*asin($1/(2*earth())) END'; + +CREATE FUNCTION gc_to_sec(float8) +RETURNS float8 +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT CASE WHEN $1 < 0 THEN 0::float8 WHEN $1/earth() > pi() THEN 2*earth() ELSE 2*earth()*sin($1/(2*earth())) END'; + +CREATE FUNCTION ll_to_earth(float8, float8) +RETURNS earth +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT cube(cube(cube(earth()*cos(radians($1))*cos(radians($2))),earth()*cos(radians($1))*sin(radians($2))),earth()*sin(radians($1)))::earth'; + +CREATE FUNCTION latitude(earth) +RETURNS float8 +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT CASE WHEN cube_ll_coord($1, 3)/earth() < -1 THEN -90::float8 WHEN cube_ll_coord($1, 3)/earth() > 1 THEN 90::float8 ELSE degrees(asin(cube_ll_coord($1, 3)/earth())) END'; + +CREATE FUNCTION longitude(earth) +RETURNS float8 +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT degrees(atan2(cube_ll_coord($1, 2), cube_ll_coord($1, 1)))'; + +CREATE FUNCTION earth_distance(earth, earth) +RETURNS float8 +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT sec_to_gc(cube_distance($1, $2))'; + +CREATE FUNCTION earth_box(earth, float8) +RETURNS cube +LANGUAGE SQL +IMMUTABLE STRICT +PARALLEL SAFE +AS 'SELECT cube_enlarge($1, gc_to_sec($2), 3)'; + +--------------- geo_distance + +CREATE FUNCTION geo_distance (point, point) +RETURNS float8 +LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE AS 'MODULE_PATHNAME'; + +--------------- geo_distance as operator <@> + +CREATE OPERATOR <@> ( + LEFTARG = point, + RIGHTARG = point, + PROCEDURE = geo_distance, + COMMUTATOR = <@> +); |