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: mysql, odbc, sqlite, pg, ogr, dbf
           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

SEE ALSO

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

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 22:55:37 +0100 (Fri, 19 Dec 2014) $

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       © 2003-2016 GRASS Development Team, GRASS GIS 7.0.3 Reference Manual