Provided by: grass-doc_7.6.0-1_all bug

NAME  - Creates topology for vector map.
       Optionally also checks for topological errors.


       vector, topology, geometry

SYNOPSIS --help  [-e]  map=name  [error=name]  option=string[,string,...]  [--overwrite]  [--help]
       [--verbose]  [--quiet]  [--ui]

           Extensive checks for topological errors
           Perform in-depth checks for topological errors when building topology

           Allow output files to overwrite existing files

           Print usage summary

           Verbose module output

           Quiet module output

           Force launching GUI dialog

       map=name [required]
           Name of vector map

           Name for output vector map where erroneous vector features are written to

       option=string[,string,...] [required]
           Build topology or dump topology or indices to standard output
           Options: build, dump, sdump, cdump, fdump
           Default: build
           build: build topology
           dump: write topology to stdout
           sdump: write spatial index to stdout
           cdump: write category index to stdout
           fdump: write feature index to stdout (OGR simple-feature-based formats only)

DESCRIPTION builds support files for GRASS vector maps. These support  files  supply  topology
       and category information including spatial index that are needed by other GRASS modules.

       GRASS  is generating these support files automatically, only in rare cases the user has to
       (re)build them.

       Refer to vector data processing in GRASS GIS for more information  on  GRASS  vector  data

NOTES  creates  support files only for vector maps located in the user’s current mapset.
       It’s not possible to rebuild support files  (option=build)  for  vector  maps  from  other

       In  case  of  errors,  the user can optionally generate an error vector map containing the
       erroneous vectors for later inspection.

       If error vector map is specified, checks:

           ·   isolated bondaries (which are not forming any areas),

           ·   centroids outside of area,

           ·   duplicated centroids.

       Extensive checks for topological errors (flag -e) also includes:

           ·   lines or boundaries of zero length,

           ·   intersecting boundaries, ie. overlapping areas,

           ·   areas without centroids that are not isles.


   Build topology
       Note that option=build recreates also spatial and category indices, not only topology. For
       linked OGR layers (see v.external) also feature index is created. map=urbanarea option=build
       Note that the vector map urbanarea must be located in the current mapset.

   Dump topology or indices
       Dump  options  print topology, spatial, category or feature index to standard output. Such
       information can be printed also for vector maps from other mapsets. A description  of  the
       vector  topology  is  available  in  the  GRASS GIS 7 Programmer’s Manual, section "Vector
       library topology management". map=urbanarea option=dump

SEE ALSO,, v.edit, v.split

       See also wxGUI vector digitizer.


       Dave Gerdes, U.S.Army Construction Engineering Research Laboratory,
       Michael Higgins, U.S.Army Construction Engineering Research Laboratory,
       Radim Blazek, ITC-irst, Trento, Italy

       Last changed: $Date: 2016-03-08 09:06:33 +0100 (Tue, 08 Mar 2016) $


       Available at: source code (history)

       Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual