Thanks for all of your responses... we're a trying some of your suggestions, using some tools to accomplish this task. I think we're close enough now. (the polygon shapefile is almost correctly generated from a shape with a bunch of lines which compose closed boundaries of polygons).
On Mon, Nov 26, 2012 at 2:53 PM, Joaquim Luis <[email protected]> wrote: > GMT5 has a tool called gmtstitch that could perhaps help doing the job, > but I never played enough with it to be more positive about its capacities. > > Joaquim > > > 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 <[email protected]> > >> 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 <[email protected]> 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 < >> [email protected]> >> > wrote: >> >> >> >> Can anybody help me? >> >> >> >> >> >> 2012/11/23 Alisson Barbosa <[email protected]> >> >>> >> >>> 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 >> >> [email protected] >> >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> > >> > >> > >> > _______________________________________________ >> > gdal-dev mailing list >> > [email protected] >> > 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 > > > > > _______________________________________________ > gdal-dev mailing > [email protected]http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev >
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