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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.
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