PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual123 / 310--Nothing happens to an already 3D geometrySELECT ST_AsEWKT(ST_Force_3DZ(ST_GeomFromEWKT(’CIRCULARSTRING(1 1 2, 2 3 2, 4 5 2, 6 7 2, 5 ←↪6 2)’)));st_asewkt-----------------------------------------------CIRCULARSTRING(1 1 2,2 3 2,4 5 2,6 7 2,5 6 2)SELECT ST_AsEWKT(ST_Force_3DZ(’POLYGON((0 0,0 5,5 0,0 0),(1 1,3 1,1 3,1 1))’));st_asewkt--------------------------------------------------------------POLYGON((0 0 0,0 5 0,5 0 0,0 0 0),(1 1 0,3 1 0,1 3 0,1 1 0))See AlsoST_AsEWKT, ST_Force_2D, ST_Force_3DM, ST_Force_3D7.5.6 ST_Force_3DMST_Force_3DM — Forces the geometries into XYM mode.Synopsisgeometry ST_Force_3DM(geometry geomA);DescriptionForces the geometries into XYM mode. If a geometry has no M component, then a 0 M coordinate is tacked on. If it has a Zcomponent, then Z is removedThis method supports Circular Strings and CurvesExamples--Nothing happens to an already 3D geometrySELECT ST_AsEWKT(ST_Force_3DM(ST_GeomFromEWKT(’CIRCULARSTRING(1 1 2, 2 3 2, 4 5 2, 6 7 2, 5 ←↪6 2)’)));st_asewkt------------------------------------------------CIRCULARSTRINGM(1 1 0,2 3 0,4 5 0,6 7 0,5 6 0)SELECT ST_AsEWKT(ST_Force_3DM(’POLYGON((0 0 1,0 5 1,5 0 1,0 0 1),(1 1 1,3 1 1,1 3 1,1 1 1) ←↪)’));st_asewkt---------------------------------------------------------------POLYGONM((0 0 0,0 5 0,5 0 0,0 0 0),(1 1 0,3 1 0,1 3 0,1 1 0))