[gdal-dev] MULTILINESTRING to MULTIPOLYGON using ogr2ogr

[Alisson Barbosa]

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.halls at 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 <hbobenicio at 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.uece at gmail.com
> >
> > wrote:
> >>
> >> Can anybody help me?
> >>
> >>
> >> 2012/11/23 Alisson Barbosa <alisson.uece at 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
> >>
> >>
> >>
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> >> http://lists.osgeo.org/mailman/listinfo/gdal-dev
> >
> >
> >
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>
>
> --
>
> ----------------------------------------------------------------------------------------------------------------
> 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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