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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:
Point
:
POINT(15 20) |
Note that point coordinates are specified with no separating comma.
LineString
with four points:
LINESTRING(0 0, 10 10, 20 25, 50 60) |
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)) |
MultiPoint
with three Point
values:
MULTIPOINT(0 0, 20 20, 60 60) |
MultiLineString
with two LineString
values:
MULTILINESTRING((10 10, 20 20), (15 15, 30 15)) |
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))) |
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 may be found in the OGC specification document referenced near the beginning of this chapter.