From: Regina Obe Date: Sun, 19 Oct 2008 14:40:34 +0000 (+0000) Subject: Move over remainder of Geometry Accessors to new section. Fix ST_MemUnion (really... X-Git-Tag: 1.4.0b1~601 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3872b77f9de6650696c4daadac397c39e309840d;p=postgis Move over remainder of Geometry Accessors to new section. Fix ST_MemUnion (really ST_MemGeomUnion), correct mistake in ST_SymDifference git-svn-id: http://svn.osgeo.org/postgis/trunk@3141 b70326c6-7e19-0410-871a-916f4a2858ee --- diff --git a/doc/reference.xml b/doc/reference.xml index 6d91850c5..0d4487ae3 100644 --- a/doc/reference.xml +++ b/doc/reference.xml @@ -92,97 +92,6 @@ - - Geometry Accessors - - - - ST_IsEmpty(geometry) - - - Returns 1 (TRUE) if this Geometry is the empty geometry . If - true, then this Geometry represents the empty point set - i.e. - GEOMETRYCOLLECTION(EMPTY). - - OGC SPEC s2.1.1.1 - - - - - ST_IsSimple(geometry) - - - Returns 1 (TRUE) if this Geometry has no anomalous geometric - points, such as self intersection or self tangency. - - Performed by the GEOS module - - OGC SPEC s2.1.1.1 - - - - - GeometryType(geometry) - - - Returns the type of the geometry as a string. Eg: - 'LINESTRING', 'POLYGON', 'MULTIPOINT', etc. - - OGC SPEC s2.1.1.1 - Returns the name of the instantiable - subtype of Geometry of which this Geometry instance is a member. - The name of the instantiable subtype of Geometry is returned as a - string. - - - This function also indicates if the geometry is measured, - by returning a string of the form 'POINTM'. - - - - - - ST_X(geometry) - - - Return the X coordinate of the point. Input must be a - point. - - - - - ST_Y(geometry) - - - Return the Y coordinate of the point. Input must be a - point. - - - - - ST_Z(geometry) - - - Return the Z coordinate of the point, or NULL if not - available. Input must be a point. - - - - - ST_M(geometry) - - - Return the M coordinate of the point, or NULL if not - available. Input must be a point. - - - This is not (yet) part of the OGC spec, but is listed here - to complete the point coordinate extractor function list. - - - - - - Geometry Constructors @@ -1322,38 +1231,6 @@ WHERE n*100.00/length < 1; - - ST_IsEmpty - - - Test if an ST_Geometry value corresponds to the empty - set. - - - SQL-MM defines the result of ST_IsEmpty(NULL) to be 0, while - PostGIS returns NULL. - - - SQL-MM 3: 5.1.7 - - - - - ST_IsSimple - - - Test if an ST_Geometry value has no anomalous geometric - points, such as self intersection or self tangency. - - - SQL-MM defines the result of ST_IsSimple(NULL) to be 0, - while PostGIS returns NULL. - - - SQL-MM 3: 5.1.8 - - - ST_LineFromText @@ -1506,27 +1383,7 @@ WHERE n*100.00/length < 1; SQL-MM 3: 5.1.36 - - - ST_X - - - Returns the x coordinate value of an ST_Point value. - - SQL-MM 3: 6.1.3 - - - - - ST_Y - - - Returns the y coordinate value of an ST_Point value. - - SQL-MM 3: 6.1.4 - - - + diff --git a/doc/reference_new.xml b/doc/reference_new.xml index 440e21d23..4659c5de5 100644 --- a/doc/reference_new.xml +++ b/doc/reference_new.xml @@ -1644,7 +1644,65 @@ SELECT ST_PointFromText('POINT(-71.064544 42.28787)', 4326); - Geometry Accessors + Geometry Accessors + + + + GeometryType + + eturns the type of the geometry as a string. Eg: + 'LINESTRING', 'POLYGON', 'MULTIPOINT', etc. + + + + + + text GeometryType + geometry geomA + + + + + + Description + + Returns the type of the geometry as a string. Eg: + 'LINESTRING', 'POLYGON', 'MULTIPOINT', etc. + + OGC SPEC s2.1.1.1 - Returns the name of the instantiable + subtype of Geometry of which this Geometry instance is a member. + The name of the instantiable subtype of Geometry is returned as a + string. + + + This function also indicates if the geometry is measured, + by returning a string of the form 'POINTM'. + + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. + + + + + + Examples + + + + + + + See Also + + + ST_Boundary @@ -2333,6 +2391,89 @@ postgis=# SELECT ST_IsClosed('MULTIPOINT((0 0), (1 1))'::geometry); + + + + ST_IsEmpty + + Returns true if this Geometry is an empty geometry . If + true, then this Geometry represents the empty point set - i.e. + GEOMETRYCOLLECTION(EMPTY). + + + + + + + boolean ST_IsEmpty + geometry geomA + + + + + + Description + + Returns true if this Geometry is an empty geometry . If + true, then this Geometry represents an empty geometry collection, polygon, point etc. + + SQL-MM defines the result of ST_IsEmpty(NULL) to be 0, while + PostGIS returns NULL. + + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. OGC SPEC s2.1.1.1 + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3: 5.1.7 + + + + + + Examples + + +SELECT ST_IsEmpty('GEOMETRYCOLLECTION(EMPTY)'); + st_isempty +------------ + t +(1 row) + + SELECT ST_IsEmpty(ST_GeomFromText('POLYGON EMPTY')); + st_isempty +------------ + t +(1 row) + +SELECT ST_IsEmpty(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))')); + + st_isempty +------------ + f +(1 row) + + SELECT ST_IsEmpty(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))')) = false; + ?column? +---------- + t +(1 row) + + + + + @@ -2410,6 +2551,81 @@ FROM (SELECT 'LINESTRING(0 0, 0 1, 1 0, 1 1, 0 0)'::geometry AS the_geom) AS foo + + + + + ST_IsSimple + + Returns (TRUE) if this Geometry has no anomalous geometric + points, such as self intersection or self tangency. + + + + + + boolean ST_IsSimple + geometry geomA + + + + + + Description + + Returns true if this Geometry has no anomalous geometric + points, such as self intersection or self tangency. + + + SQL-MM defines the result of ST_IsSimple(NULL) to be 0, + while PostGIS returns NULL. + + + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. OGC SPEC s2.1.1.1 + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3: 5.1.8 + + + + + + + This function supports 3d and will not drop the z-index. + + + + + Examples + + SELECT ST_IsSimple(ST_GeomFromText('POLYGON((1 2, 3 4, 5 6, 1 2))')); + st_issimple +------------- + t +(1 row) + + SELECT ST_IsSimple(ST_GeomFromText('LINESTRING(1 1,2 2,2 3.5,1 3,1 2,2 1)')); + st_issimple +------------- + f +(1 row) + + + + @@ -2477,6 +2693,79 @@ NOTICE: Self-intersection at or near point 0 0 + + + ST_M + + Return the M coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + float ST_M + geometry a_point + + + + + + Description + + Return the M coordinate of the point, or NULL if not + available. Input must be a point. + + + This is not (yet) part of the OGC spec, but is listed here + to complete the point coordinate extractor function list. + + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3 New standard: ? + + + + + + + This function supports 3d and will not drop the z-index. + + + + + Examples + SELECT ST_M(ST_GeomFromEWKT('POINT(1 2 3 4)')); + st_m +------ + 4 +(1 row) + + + + + + + See Also + + , , , + + + ST_NDims @@ -3046,6 +3335,204 @@ Line[ZB] with 2 points : Polygon[ZB] with 1 rings + + + + ST_X + + Return the X coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + float ST_X + geometry a_point + + + + + + Description + + Return the X coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3 standard: SQL-MM 3: 6.1.3 + + + + + + + This function supports 3d and will not drop the z-index. + + + + + Examples + SELECT ST_X(ST_GeomFromEWKT('POINT(1 2 3 4)')); + st_x +------ + 1 +(1 row) + + + + + + + See Also + + , , , + + + + + + ST_Y + + Return the Y coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + float ST_X + geometry a_point + + + + + + Description + + Return the Y coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + + This method implements the OpenGIS Simple Features + Implementation Specification for SQL. + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3 standard: SQL-MM 3: 6.1.4 + + + + + + + This function supports 3d and will not drop the z-index. + + + + + Examples + SELECT ST_Y(ST_GeomFromEWKT('POINT(1 2 3 4)')); + st_y +------ + 2 +(1 row) + + + + + + + See Also + + , , , + + + + + + ST_Z + + Return the Z coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + float ST_Z + geometry a_point + + + + + + Description + + Return the Z coordinate of the point, or NULL if not + available. Input must be a point. + + + + + + + + + This method implements the SQL/MM specification: + SQL-MM 3 standard New Spec: ? + + + + + + + This function supports 3d and will not drop the z-index. + + + + + Examples + SELECT ST_Z(ST_GeomFromEWKT('POINT(1 2 3 4)')); + st_y +------ + 3 +(1 row) + + + + + + + See Also + + , , , + + + @@ -6533,9 +7020,9 @@ FROM country - + - ST_MemUnion + ST_MemGeomUnion Same as ST_Union, only memory-friendly (uses less memory and more processor time). @@ -6544,7 +7031,7 @@ FROM country - geometry ST_MemUnion + geometry ST_MemGeomUnion geometry set geomfield @@ -6856,7 +7343,6 @@ FROM (SELECT ST_Buffer('POINT(1 3)', 10,12) As the_geom) As foo; that do not intersect. It is called a symmetric difference because ST_SymDifference(A,B) = ST_SymDifference(B,A). One can think of this as ST_Union(geomA,geomB) - ST_Intersection(A,B). - Note - order matters. B - A will always return a portion of B Performed by the GEOS module