NAME
v.llabel - Bulk-labels unlabeled lines in a binary GRASS vector file.
(GRASS Vector Program)
SYNOPSIS
v.llabel
v.llabel help
v.llabel [-in] map=name
[value=value]
DESCRIPTION
v.llabel allows the user to bulk-label currently
unlabeled lines (not area features) in a binary GRASS
vector file (i.e., a dig file). The user must run
v.support
on the vector file before running
v.llabel if any modifications have been made to the
file since the last time
v.support
was run on it, to
ensure that all lines are properly identified in the file
topology.
The program also runs
v.support
on the vector file
after labelling so that the changes will be made evident.
v.support
builds GRASS support files for (binary) GRASS vector
data files. These support files supply topology (dig_plus)
and category (dig_att) information that are needed by other GRASS
programs
(e.g., by v.digit,
v.to.rast, etc.).
OPTIONS
Program parameters and flags have the following meanings.
Flags:
- -i
- Label lines incrementally. For each unique, unlabeled line in the
vector file, increment the category value by one, starting from the
initial default or user-assigned value.
- -n
- Do not run
v.support.
There may occasionally be instances where the user
prefers not to run
v.support
immediately.
Parameters:
- map=name
- Name of binary GRASS vector data file whose unlabeled
lines are to be labelled. This map layer must exist in the
user's current GRASS mapset.
- value=value
- The category value to be assigned to all unlabeled lines in the
vector map layer. If the -i flag is set, v.llabel
will increment the initial value by one for each unique unlabeled
polygon in the vector map.
Default: 1
The user can run this program non-interactively by specifying parameter
values (and optionally, the flag setting) on the command line.
Alternately, the user can simply type the command v.llabel on
the command line. In this event, the program will prompt the user to
enter parameter values and flag settings.
NOTES
A dig_plus file must be created for each imported vector map
before it can be used in
v.digit.
Topological information for GRASS vector files can also be built using
option 4 of the
v.import.
program.
The user can bulk-label unlabeled line features in a
binary vector file using
v.digit.
SEE ALSO
v.digit,
v.in.ascii,
v.support, and
v.alabel
AUTHORS
James Darrell McCauley, Agricultural
Engineering, Purdue University
Dave Gerdes, U.S.Army Construction Engineering
Research Laboratory