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v.build

Creates topology for vector map.

Optionally also checks for topological errors.

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

Example:

v.build map=name option=build

grass.script.run_command("v.build", map, error=None, option="build", flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("v.build", map="name", option="build")

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
    Allowed values: 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)
-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
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

map : str, required
    Name of vector map
    Used as: input, vector, name
error : str, optional
    Name for output vector map where erroneous vector features are written to
    Used as: output, vector, name
option : str | list[str], required
    Build topology or dump topology or indices to standard output
    Allowed values: build, dump, sdump, cdump, fdump
    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)
    Default: build
flags : str, optional
    Allowed values: e
    e
        Extensive checks for topological errors
        Perform in-depth checks for topological errors when building topology
overwrite: bool, optional
    Allow output files to overwrite existing files
    Default: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

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 boundaries (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, i.e. overlapping areas,
  • areas without centroids that are not isles.

EXAMPLES

Build topology

Note that option=build also recreates 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 also be printed for vector maps from other mapsets. A description of the vector topology is available in the GRASS GIS 8 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, v.support

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)
Latest change: Saturday Mar 15 07:34:27 2025 in commit db9ad65