PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual107 / 3105340 | Self-intersection [42 5]5350 | Self-intersection [52 5]--simple exampleSELECT ST_IsValidReason(’LINESTRING(220227 150406,2220227 150407,222020 150410)’);st_isvalidreason------------------Valid GeometrySee AlsoST_IsValid, ST_Summary7.4.17 ST_MST_M — Return the M coordinate of the point, or NULL if not available. Input must be a point.Synopsisfloat ST_M(geometry a_point);DescriptionReturn the M coordinate of the point, or NULL if not available. Input must be a point.NoteThis 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 1.1.This method implements the SQL/MM specification.This function supports 3d and will not drop the z-index.ExamplesSELECT ST_M(ST_GeomFromEWKT(’POINT(1 2 3 4)’));st_m------4(1 row)See AlsoST_GeomFromEWKT, ST_X, ST_Y, ST_Z