mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-12-15 08:20:16 +08:00
458857cc9d
We have seen one too many reports of people trying to use 9.1 extension files in the old-fashioned way of sourcing them in psql. Not only does that usually not work (due to failure to substitute for MODULE_PATHNAME and/or @extschema@), but if it did work they'd get a collection of loose objects not an extension. To prevent this, insert an \echo ... \quit line that prints a suitable error message into each extension script file, and teach commands/extension.c to ignore lines starting with \echo. That should not only prevent any adverse consequences of loading a script file the wrong way, but make it crystal clear to users that they need to do it differently now. Tom Lane, following an idea of Andrew Dunstan's. Back-patch into 9.1 ... there is not going to be much value in this if we wait till 9.2.
92 lines
3.0 KiB
SQL
92 lines
3.0 KiB
SQL
/* contrib/earthdistance/earthdistance--1.0.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
|
|
AS 'SELECT ''6378168''::float8';
|
|
|
|
-- Astromers 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) < '10e-7'::float8);
|
|
|
|
CREATE FUNCTION sec_to_gc(float8)
|
|
RETURNS float8
|
|
LANGUAGE SQL
|
|
IMMUTABLE STRICT
|
|
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
|
|
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
|
|
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
|
|
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
|
|
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
|
|
AS 'SELECT sec_to_gc(cube_distance($1, $2))';
|
|
|
|
CREATE FUNCTION earth_box(earth, float8)
|
|
RETURNS cube
|
|
LANGUAGE SQL
|
|
IMMUTABLE STRICT
|
|
AS 'SELECT cube_enlarge($1, gc_to_sec($2), 3)';
|
|
|
|
--------------- geo_distance
|
|
|
|
CREATE FUNCTION geo_distance (point, point)
|
|
RETURNS float8
|
|
LANGUAGE C IMMUTABLE STRICT AS 'MODULE_PATHNAME';
|
|
|
|
--------------- geo_distance as operator <@>
|
|
|
|
CREATE OPERATOR <@> (
|
|
LEFTARG = point,
|
|
RIGHTARG = point,
|
|
PROCEDURE = geo_distance,
|
|
COMMUTATOR = <@>
|
|
);
|