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.
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