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18.3.1. Well-Known Text (WKT) Format

The Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form.

Examples of WKT representations of geometry objects:

  • A Point:

    POINT(15 20)
    

    Note that point coordinates are specified with no separating comma.

  • A LineString with four points:

    LINESTRING(0 0, 10 10, 20 25, 50 60)
    

    Note that point coordinate pairs are separated by commas.

  • A Polygon with one exterior ring and one interior ring:

    POLYGON((0 0,10 0,10 10,0 10,0 0),(5 5,7 5,7 7,5 7, 5 5))
    
  • A MultiPoint with three Point values:

    MULTIPOINT(0 0, 20 20, 60 60)
    
  • A MultiLineString with two LineString values:

    MULTILINESTRING((10 10, 20 20), (15 15, 30 15))
    
  • A MultiPolygon with two Polygon values:

    MULTIPOLYGON(((0 0,10 0,10 10,0 10,0 0)),((5 5,7 5,7 7,5 7, 5 5)))
    
  • A GeometryCollection consisting of two Point values and one LineString:

    GEOMETRYCOLLECTION(POINT(10 10), POINT(30 30), LINESTRING(15 15, 20 20))
    

A Backus-Naur grammar that specifies the formal production rules for writing WKT values can be found in the OpenGIS specification document referenced near the beginning of this chapter.


 
 
  Published under the terms of the GNU General Public License Design by Interspire