v.patch allows the user to combine any number of
vector map layers together to create one composite vector
map layer.
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 (tool=snap,break,rmdupl).
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