11.3.1 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 are:

• 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)
  

• 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 grammer that specifies the formal production rules for writing WKT values may be found in the OGC specification document referenced near the beginning of this chapter.

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