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

6       v.lrs.where  - Find line id and real km+offset for given points in vec‐
7       tor 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]
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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           Line layer Default: 1
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28       player=integer
29           Point layer Default: 1
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31       rstable=string
32           Name of the reference system table
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34       thresh=float
35           Maximum distance to nearest line Default: 1000
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DESCRIPTION

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

42       This example is written for the Spearfish  dataset  (it  continues  the
43       example from v.lrs.create).
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45       In this example, the 'route_lrs' shall be queried for unknown positions
46       (points, stored in the map newpoints) along the LRS:
47       # generate query points
48       echo "590866.15|4926737.0
49       590933|4927133" | v.in.ascii out=newpoints
50       v.lrs.where lines=route_lrs points=newpoints rstable=route_lrs
51       pcat|lid|mpost|offset
52       pcat|lid|mpost|offset
53       1|22|4.000000+212.091461
54       2|22|6.000000+188.112093
55       # verification
56       g.region vect=route_lrs n=n+100 s=s-100 -p
57       d.erase
58       d.vect route_lrs
59       d.vect busstops disp=attr attr=cat size=10 bg=white lcol=blue yref=bot‐
60       tom
61       d.vect busstops icon=basic/circle fcol=blue
62       d.vect newpoints col=red
63       # measure distance to previous bus stop
64       d.measure
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SEE ALSO

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

73       Radim Blazek, ITC-irst/MPA Solutions
74       Documentation  update  (based  on  above  journal article and available
75       fragments): Markus Neteler
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77       Last changed: $Date: 2007/06/28 15:42:47 $
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79       Full index
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83GRASS 6.2.2                                                     v.lrs.where(1)