[Freegis-list] polygonize a set of lines

[Brent Wood]

--- Eduardo Patto Kanegae <epk.lists at gmail.com> wrote:

> Hi folks,
> 
> I have a CAD line layer describing the limits of a soil map. It's a
> line layer because the first need was for printing only.
> 
> Now I need to put this soil map as a polygon into a GIS dataset.
> 
> Does anybody recommend any free gis tool that could be usefull to do that?

Hi Eduardo,


I haven't tried it, but I believe GRASS has some capabilities in this area,
once you convert the CAD data to a supported format.

You could try PostGIS, if you can get your data into a postgis table somehow,
there are commands to do this. 

For an Open Source (Windows) tool to do the conversion to shapefile, try 
http://www.happysquirrel.com/index.php?feature=dxf2shp
  or see
http://software.geocomm.com/translators/cad-dxf/

In PostGIS, see

http://postgis.refractions.net/docs/ch06.html#id2843565

The functions polygonize, makepolygon & buildarea can probably do what you
want.



You may also find something useful at 

http://software.geocomm.com/topology/


HTH,

  Brent Wood