v.lrs.segment(1)

NAME
v.lrs.segment - Creates points/segments from input lines, linear reference system and positions read from stdin or a file.

KEYWORDS
vector, linear reference system, network

SYNOPSIS
v.lrs.segment
v.lrs.segment --help
v.lrs.segment input=name output=name [llayer=string] [rsdriver=string] [rsdatabase=string] rstable=string [file=name] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

  Flags:

--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 [required]
    Name of input vector map
    Input vector map containing lines

output=name [required]
    Output vector map where segments will be written

llayer=string
    Layer number or name
    Line layer
    Default: 1

rsdriver=string
    Driver name for reference system table
    Options: dbf, ogr, pg, sqlite
    Default: sqlite

rsdatabase=string
    Database name for reference system table
    Default: $GISDBASE/$LOCATION_NAME/$MAPSET/sqlite/sqlite.db

rstable=string [required]
    Name of the reference system table

file=name
    Name of file containing segment rules. If not given, read from stdin.

DESCRIPTION
v.lrs.segment creates points/segments from input lines, linear reference system and positions read from standard in or a file.

The format is as follows:

P <point_id> <line_id> <milepost>+<offset> [<side offset>]
L <segment_id> <line_id> <milepost>+<offset> <milepost>+<offset> [<side offset>]

NOTES
For more information and examples see the help page for v.lrs.segment’s sister module, v.segment.

EXAMPLE
This example is written for the Spearfish dataset (it continues the example from v.lrs.create).

In this example, the ’route_lrs’ shall be extended for a new position (point) along the LRS after bus stop 4:

# new point on LRS
echo "P 7 22 4+180" | v.lrs.segment route_lrs out=route_lrs_new rstable=route_lrs
g.region vector=route_lrs n=n+100 s=s-100 -p
d.erase
# existing LRS
d.vect route_lrs
d.vect busstops disp=attr attr=cat size=10 bg=white lcol=blue yref=bottom
d.vect busstops icon=basic/circle fcol=blue
db.select table=route_lrs
# show modified map
d.vect route_lrs_new col=red

TODO
Figure out how to merge result into existing LRS map and table.

SEE ALSO
LRS tutorial,
Introducing the Linear Reference System in GRASS,
v.lrs.create, v.lrs.where, v.lrs.label, v.segment

AUTHOR
Radim Blazek

SOURCE CODE

Available at: v.lrs.segment source code (history)

Accessed: Tuesday Jun 16 04:05:19 2026

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