1v.lrs.where(1)                Grass User's Manual               v.lrs.where(1)
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NAME

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

10       vector, LRS, networking
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SYNOPSIS

13       v.lrs.where
14       v.lrs.where help
15       v.lrs.where lines=name points=name  [llayer=integer]   [player=integer]
16       rstable=string  [thresh=float]   [--verbose]  [--quiet]
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18   Parameters:
19       lines=name
20           Input vector map containing lines
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22       points=name
23           Input vector map containing points
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25       llayer=integer
26           Layer number
27           Line layer
28           Default: 1
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30       player=integer
31           Layer number
32           Point layer
33           Default: 1
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35       rstable=string
36           Name of the reference system table
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38       thresh=float
39           Maximum distance to nearest line
40           Default: 1000
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DESCRIPTION

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

47       This example is written for the Spearfish  dataset  (it  continues  the
48       example from v.lrs.create).
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50       In this example, the 'route_lrs' shall be queried for unknown positions
51       (points, stored in the map newpoints) along the LRS:
52       # generate query points
53       echo "590866.15|4926737.0
54       590933|4927133" | v.in.ascii out=newpoints
55       v.lrs.where lines=route_lrs points=newpoints rstable=route_lrs
56       pcat|lid|mpost|offset
57       pcat|lid|mpost|offset
58       1|22|4.000000+212.091461
59       2|22|6.000000+188.112093
60       # verification
61       g.region vect=route_lrs n=n+100 s=s-100 -p
62       d.erase
63       d.vect route_lrs
64       d.vect busstops disp=attr attr=cat size=10 bg=white lcol=blue yref=bot‐
65       tom
66       d.vect busstops icon=basic/circle fcol=blue
67       d.vect newpoints col=red
68       # measure distance to previous bus stop
69       d.measure
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SEE ALSO

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

78       Radim Blazek, ITC-irst/MPA Solutions
79       Documentation  update  (based  on  above  journal article and available
80       fragments): Markus Neteler
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82       Last changed: $Date: 2007-06-28 17:28:50 +0200 (Thu, 28 Jun 2007) $
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84       Full index
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86       © 2003-2008 GRASS Development Team
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90GRASS 6.3.0                                                     v.lrs.where(1)