v.digit is a vector map digitizer with TCL/TK-based graphical
user interface. Attribute tables can be directly generated while
digitizing (define in "Settings" first).
The bgcmd option is intended to be used with display (d.*) commands.
If several display commands are to be used to render the background
they should be separated with the semi-colon ';' character.
When run from the command line, these display commands will generally
need to be "quoted" as they will contain spaces (see examples).
Dead (deleted) lines: If a user deletes a line in v.digit,
it is internally only marked in the geometry file as 'dead' but it remains
there and occupies space. Any vector module used afterwards on this map
which really reads and writes vector geometry (so
not g.copy) will writes only lines
which are 'alive'.
If v.digit crashes for some reason you can repair the vector map
which was left open with the v.build module.
Start a monitor and display a raster to help setup and zoom to area of interest
Digitizing an area based on a existing raster map; creating a new vector map
v.digit -n map=name_of_new_vector_map bgcmd="d.rast map=name_of_raster"
The -n flag specifies that your vector map does not yet exist and
thus will be created with the name given by map. The bgcmd
specifies a display (d.*) command and is set in "quotes" as it contains a space.
The v.digit GUI appears and vector map "name_of_new_vector_map" is created.
After leaving v.digit, run:
The display should be cleared and the newly created vector should appear in
Digitizing a second vector, using your first vector and the raster image
The v.digit GUI appears and the layers defined with bgcmd
are displayed in the background. As the bgcmd commands are executed
as a series of commands (separated by a ";"), the last command (d.vect)
displays over the top of the earlier raster image.
v.digit -n map=name_of_second_vector \
bgcmd="d.rast map=name_of_your_raster; d.vect map=name_of_new_vector_map"
Combining bgcmd with d.save to use the existing
display as a backdrop
d.save will list the commands used to draw
the current display; cut and tr are UNIX commands which are
used to remove comments and trade newlines for semi-colons, respectively.
v.digit map=name bgcmd="`d.save -o | cut -f1 -d'#' | tr '\n' ';'`"
See also wxGUI Vector Digitizer.
Radim Blazek, ITC-Irst, Trento, Italy
Last changed: $Date$