NAME

v.lrs.where - Finds line id and real km+offset for given points in vector map using linear reference system.

KEYWORDS

vector, linear reference system, network

SYNOPSIS

v.lrs.where

v.lrs.where --help

v.lrs.where lines=name points=name [llayer= string] [player=string] [rsdriver=string] [rsdatabase=string] rstable= string [threshold=float] [--help] [-- verbose] [--quiet] [--ui]

Flags:

--help: Print usage summary

--verbose: Verbose module output

--quiet: Quiet module output

--ui: Force launching GUI dialog

Parameters:

lines=name [required]: Name of input vector map

Input vector map containing lines

points=name [required]: Name of input vector map

Input vector map containing points

llayer=string: Layer number or name

Line layer

Default: 1

player=string: Layer number or name

Point 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

threshold=float: Maximum distance to nearest line

Default: 1000

DESCRIPTION

v.lrs.where identifies line id and real milepost+offset for points in vector map using linear reference system.

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 queried for unknown positions (points, stored in the map newpoints) along the LRS:

# generate query points
echo "590866.15|4926737.0
590933|4927133" | v.in.ascii out=newpoints
v.lrs.where lines=route_lrs points=newpoints rstable=route_lrs
pcat|lid|mpost|offset
pcat|lid|mpost|offset
1|22|4.000000+212.091461
2|22|6.000000+188.112093
# verification
g.region vector=route_lrs n=n+100 s=s-100 -p
d.erase
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
d.vect newpoints col=red
# measure distance to previous bus stop:
# use measuring tool in graphical user interface

AUTHOR

Radim Blazek, ITC-irst/MPA Solutions

Documentation update (based on above journal article and available fragments): Markus Neteler

Last changed: $Date: 2014-12-19 22:17:36 +0100 (Fri, 19 Dec 2014) $

SOURCE CODE

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