NAME

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

KEYWORDS

       vector, topology, geometry

SYNOPSIS

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

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

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       map=name [required]
           Name of vector map

       error=name
           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

       v.build 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 model.

NOTES

       v.build  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 mapsets.

       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, v.build 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.

EXAMPLES

   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.
       v.build 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".
       v.build map=urbanarea option=dump

SEE ALSO

        v.build.all, v.build.polylines, v.edit, v.split

       See also wxGUI vector digitizer.

AUTHORS

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

SOURCE CODE

       Available at: v.build source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual