NAME

       v.patch  - Creates a new vector map by combining other vector maps.

KEYWORDS

       vector, geometry, level1

SYNOPSIS

       v.patch
       v.patch --help
       v.patch  [-nzeab]  input=name[,name,...]  output=name  [bbox=name]   [--overwrite]  [--help]  [--verbose]
       [--quiet]  [--ui]

   Flags:
       -n
           Do not expect input with topology
           Applicable when input is points without topology

       -z
           Expect z coordinate even when not using topology
           Applicable when input is points with z coordinate but without topology

       -e
           Copy also attribute table
           Only the table of layer 1 is currently supported

       -a
           Append files to existing file (overwriting existing files must be activated)

       -b
           Do not build topology
           Advantageous when handling a large number of points

       --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:
       input=name[,name,...] [required]
           Name of input vector map(s)
           Or data source(s) for direct OGR access

       output=name [required]
           Name for output vector map

       bbox=name
           Name for output vector map where bounding boxes of input vector maps are written to

DESCRIPTION

       v.patch allows the user to combine any number of vector maps together to create one composite vector map.
       If the table structures are identical, attributes are transferred to the new table.

NOTES

       Any vectors that are duplicated among the maps being patched together (e.g., border lines) will  have  to
       be edited or removed after v.patch is run. Such editing can be done automatically using v.clean.

       Lines may need to be snapped with v.clean tool=snap,break,rmdupl.

       Boundaries  may  need  to  be  cleaned with v.clean tool=break,rmdupl,rmsa repeatedly until the rmsa tool
       (Remove small angles at nodes) no longer modifies any boundaries. If vector topology is still not  clean,
       boundaries may also need to be snapped with v.clean tool=snap,break,rmdupl.

       When  using the -e flag, v.patch shifts category (cat) values in the output so that category numbers from
       the different input maps do not overlap. This shift is  applied  to  both  the  category  values  of  the
       features  and  the category values in the attribute tables. Hence, there is no need to run v.category and
       v.db.update beforehand.

       When using the -a flag, the user has to make sure that the features in the different maps  added  to  the
       output  map do not have overlapping category numbers, unless identical category numbers reflect identical
       attributes, otherwise the attributes of the added maps  are  lost.  To  avoid  this,  the  user  can  use
       v.category option=sum to change category values of some of the maps before patching.

EXAMPLES

       Patch together two maps with mixed feature types:
          v.patch input=geology,streams out=geol_streams
       Append one map to another:
          g.copy vect=roads,transport
          v.patch -a input=railroads output=transport --overwrite

SEE ALSO

        v.clean, v.build, v.select, v.overlay

AUTHORS

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

SOURCE CODE

       Available at: v.patch source code (history)

       Accessed: Monday Apr 01 03:08:50 2024

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       © 2003-2024 GRASS Development Team, GRASS GIS 8.3.2 Reference Manual

GRASS 8.3.2                                                                                      v.patch(1grass)