---
name: "v.lrs.segment"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/v.lrs.segment"
---

# v.lrs.segment(1grass)

Creates points/segments from input lines, linear reference system and positions read from stdin or a file.

## 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, mysql, odbc, 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

*v.lrs.create,* *v.lrs.where,* *v.lrs.label,* *v.segment*

*LRS tutorial,*\
 *Introducing the Linear Reference System in GRASS*

## AUTHOR

Radim Blazek

## SOURCE CODE

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

Accessed: Monday Feb 24 17:51:17 2025

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