I want a command line tool to do the same thing that "Feature to Polygon" of ArcGIS or Polygonizer plugin of Quantum GIS does. Is there any tool for this?
2012/11/26 Peter Halls <p.ha...@york.ac.uk> > Alisson, Hugo, > > I think a reason for the lack of response is that the operation > you need is a tad more involved than is supported by ogr2ogr - which > performs simple geometrical operations but is really designed to > perform format translations. > > To go from a spaghetti of lines to polygons requires the > identification of each future polygon boundary, the assembly of the > polygon boundary, ensuring that it closes and writing out the new > polygon. This much ogr2ogr does. To go to multipolygons, however, > requires the further assembly of the related polygons into a combined > polygon - for example, islands in a lake. All of this relies on the > existence of attribute values to identify what belongs to what. > Further complication is involved if the resultant polygons overlap and > it is required that these overlaps be identified, although this is not > required for a polygon shapefile. > > As this process may require intelligence based upon more complex > attribute relationships, it is probably the case that a program > (Python, Java, C++, etc) is required to implement the specific logic > required. > > If you want to read up on the operations involved, one of the most > approachable texts is 'GIS Basics' by Steve Wise (Taylor & Francis, > 2002). The good news is that there are calls in the OGR API to > implement each of the steps involved. > > Best wishes, > > Peter > > On 26 November 2012 12:24, Hugo Benicio <hbobeni...@gmail.com> wrote: > > I'm facing a similar problem when trying to convert a shapefile > containing > > lines to a shapefile containing polygons. > > No progress. > > If you solve it, please, let me know! > > > > Thanks in advance. > > > > > > On Mon, Nov 26, 2012 at 8:47 AM, Alisson Barbosa <alisson.u...@gmail.com > > > > wrote: > >> > >> Can anybody help me? > >> > >> > >> 2012/11/23 Alisson Barbosa <alisson.u...@gmail.com> > >>> > >>> Hi friends, > >>> > >>> I would like to transform a shape with multilinestring in a shape with > >>> polygons using ogr2ogr. > >>> > >>> Polygon to multilinestring, I use: > >>> ogr2ogr -f "ESRI Shapefile" -overwrite "C:/Users/Alisson/Basins3.shp" > >>> "C:/Users/Alisson/Basins2.shp" -sql "SELECT * FROM Basins2" > -skipfailures > >>> -nlt MULTILINESTRING > >>> > >>> This works. > >>> > >>> Multilinestring to multipolygon, I use: > >>> ogr2ogr -f "ESRI Shapefile" -overwrite "C:/Users/Alisson/polygon.shp" > >>> "C:/Users/AlissonContorno30.shp" -sql "SELECT * FROM Contorno30" > >>> -skipfailures -nlt MULTIPOLYGON > >>> > >>> But, this error appears: > >>> ERROR 1: Attempt to write non-polygon (LINESTRING) geometry to POLYGON > >>> type shapefile. > >>> > >>> Can you help me? > >>> > >>> Best regards, > >>> -- > >>> Alisson Barbosa > >>> Systems Analyst - FUNCEME > >>> M.Sc. in Computer Science - MACC > >>> Graduate in Computer Science - UECE > >>> > >>> > >> > >> > >> > >> -- > >> Alisson Barbosa > >> Systems Analyst - FUNCEME > >> M.Sc. in Computer Science - MACC > >> Graduate in Computer Science - UECE > >> > >> > >> > >> _______________________________________________ > >> gdal-dev mailing list > >> gdal-dev@lists.osgeo.org > >> http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > > > > > _______________________________________________ > > gdal-dev mailing list > > gdal-dev@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > -- > > ---------------------------------------------------------------------------------------------------------------- > Peter J Halls, GIS Advisor & Team Leader Applications Support and Training, > Information Directorate, University of York > Telephone: 01904 323806 Fax: 01904 323740 > Snail mail: Harry Fairhurst Building, University of York, > Heslington, York YO10 5DD > This message has the status of a private and personal communication > > ---------------------------------------------------------------------------------------------------------------- > -- Alisson Barbosa Systems Analyst - FUNCEME M.Sc. in Computer Science - MACC Graduate in Computer Science - UECE
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