[postgis-users] Polygons from linestrings

michael holzmann mholzmann at tiscali.de
Thu Nov 25 08:55:33 PST 2004


hello list,
I have the following problems with postgis..

1. how is it possible ( with methods like "Touches") to make Polygons or 
MultiPolygons with Spatial touches relationships from the Linestrings below? 
who can give me an SQL statement expample?

	wkb_geometry
SRID=31494; LINESTRING(x1 y1,x2 y2)
SRID=31494; LINESTRING(x2 y2,x3 y3)
SRID=31494; LINESTRING(x3 y3,x4 y4)
SRID=31494; LINESTRING(x4 y4,x1 y1)
SRID=31494; LINESTRING(x1 y1,x5 y5)
SRID=31494; LINESTRING(x5 y5,x6 y6)
SRID=31494; LINESTRING(x6 y6,x2 y2)

5 ________________ 6
  I                            I
  I                            I
  I                            I
1I________________I2
  I                            I
  I                            I
  I                            I
4I________________I3

2. can I use with Postgis 0.8.1-1 the simple feature curve? who can show me an 
example how it have to look in the Database.

Thanks a lot for every hint

michael holzmann



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