1v.net.allpairs(1) Grass User's Manual v.net.allpairs(1)
2
6 v.net.allpairs - Computes the shortest path between all pairs of nodes
7 in the network.
8
10 vector, network, shortest path
11
13 v.net.allpairs
14 v.net.allpairs --help
15 v.net.allpairs [-g] input=name output=name [arc_layer=string]
16 [node_layer=string] [cats=range] [where=sql_query] [arc_col‐
17 umn=name] [arc_backward_column=name] [node_column=string]
18 [--overwrite] [--help] [--verbose] [--quiet] [--ui]
19 Flags:
21 -g
22 Use geodesic calculation for longitude-latitude locations
23 --overwrite
25 Allow output files to overwrite existing files
26 --help
28 Print usage summary
29 --verbose
31 Verbose module output
32 --quiet
34 Quiet module output
35 --ui
37 Force launching GUI dialog
38 Parameters:
40 input=name [required]
41 Name of input vector map
42 Or data source for direct OGR access
43 output=name [required]
45 Name for output vector map
46 arc_layer=string
48 Arc layer
49 Vector features can have category values in different layers. This
50 number determines which layer to use. When used with direct OGR
51 access this is the layer name.
52 Default: 1
53 node_layer=string
55 Node layer
56 Vector features can have category values in different layers. This
57 number determines which layer to use. When used with direct OGR
58 access this is the layer name.
59 Default: 2
60 cats=range
62 Category values
63 Example: 1,3,7-9,13
64 where=sql_query
66 WHERE conditions of SQL statement without ’where’ keyword
67 Example: income < 1000 and population >= 10000
68 arc_column=name
70 Arc forward/both direction(s) cost column (number)
71 arc_backward_column=name
73 Arc backward direction cost column (number)
74 node_column=string
76 Node cost column (number)
77
79 v.net.allpairs computes the shortest path between each selected node
80 and all other selected nodes. The output is a vector with the selected
81 nodes and the shortest paths.
82
84 An attribute table is created and linked to layer arc_layer. The table
85 contains four columns: cat, from_cat, to_cat, cost. Each cat entry
86 denotes the category of the shortest path from the node with category
87 from_cat to the node with category to_cat. If points are specified by
88 cats, layer or where parameters then the table is filled only for the
89 selected points.
90 If arc_backward_column is not given then then the same costs are used
91 for forward and backward arcs.
92
94 Find shortest path along roads from selected archsites (Spearfish sam‐
95 ple dataset):
96 # prepare network: connect archsites to roads with threshold 200
97 v.net input=roads@PERMANENT points=archsites@PERMANENT \
98 output=roads_net operation=connect thresh=200
99 # verify result
100 v.category input=roads_net option=report
101 # only lines should have a category in layer 1
102 # only points should have a category in layer 2
103 # shortest path between all points with categories 1 - 5 in layer 2
104 v.net.allpairs input=roads_net cats=1-5 out=roads_net_all
105 v.db.select roads_net_all
106 Result in matrix form:
107 from\to 1 3 4 5
108 1 0 18820.386 17206.651 17373.274
109 3 18820.386 0 1739.079 9040.575
110 4 17206.651 1739.079 0 7426.84
111 5 17373.274 9040.575 7426.84 0
112
114 v.net.path, v.net.distance
115
117 Daniel Bundala, Google Summer of Code 2009, Student
118 Wolf Bergenheim, Mentor
119 Markus Metz
120 Last changed: $Date: 2014-12-24 15:11:14 +0100 (Wed, 24 Dec 2014) $
122
124 Available at: v.net.allpairs source code (history)
125 Main index | Vector index | Topics index | Keywords index | Graphical
127 index | Full index
128 © 2003-2019 GRASS Development Team, GRASS GIS 7.4.4 Reference Manual
130GRASS 7.4.4 v.net.allpairs(1)