1v.net.connectivity(1) Grass User's Manual v.net.connectivity(1)
2
6 v.net.connectivity - Computes vertex connectivity between two sets of
7 nodes in the network.
8
10 vector, network, connectivity
11
13 v.net.connectivity
14 v.net.connectivity --help
15 v.net.connectivity input=name [arc_layer=string] [node_layer=string]
16 [arc_column=name] [arc_backward_column=name] output=name [node_col‐
17 umn=name] [set1_cats=range] [set1_where=sql_query]
18 [set2_cats=range] [set2_where=sql_query] [--overwrite] [--help]
19 [--verbose] [--quiet] [--ui]
20 Flags:
22 --overwrite
23 Allow output files to overwrite existing files
24 --help
26 Print usage summary
27 --verbose
29 Verbose module output
30 --quiet
32 Quiet module output
33 --ui
35 Force launching GUI dialog
36 Parameters:
38 input=name [required]
39 Name of input vector map
40 Or data source for direct OGR access
41 arc_layer=string
43 Arc layer
44 Vector features can have category values in different layers. This
45 number determines which layer to use. When used with direct OGR
46 access this is the layer name.
47 Default: 1
48 node_layer=string
50 Node layer
51 Vector features can have category values in different layers. This
52 number determines which layer to use. When used with direct OGR
53 access this is the layer name.
54 Default: 2
55 arc_column=name
57 Arc forward/both direction(s) cost column (number)
58 arc_backward_column=name
60 Arc backward direction cost column (number)
61 output=name [required]
63 Name for output vector map
64 node_column=name
66 Node cost column (number)
67 set1_cats=range
69 Set1 category values
70 Example: 1,3,7-9,13
71 set1_where=sql_query
73 Set1 WHERE conditions of SQL statement without ’where’ keyword
74 Example: income < 1000 and population >= 10000
75 set2_cats=range
77 Category values
78 Set2 category values
79 set2_where=sql_query
81 Set2 WHERE conditions of SQL statement without ’where’ keyword
82 Example: income < 1000 and population >= 10000
83
85 v.net.connectivity computes vertex connectivity between two sets, i.e.
86 the minimum number of vertices whose removal would separate two given
87 sets.
88
90 Two sets (set1 and set2) are specified by respective layer, where and
91 cats parameters. Similarly to v.net.flow module, capacities of nodes
92 can be given by node_column option. v.net.connectivity finds the set of
93 nodes of minimum total capacitiy separating the two given sets and out‐
94 puts map containing points on the positions of these nodes. Default
95 capacity, which is used when no column is specified, is one.
96
98 The following command finds the minimum number of intersections sepa‐
99 rating roads on the left bank from roads on the right bank.
100 v.net.connectivity input=roads output=roads_conn set1_where="bank=left" \
101 set2_where="bank=right"
102 v.net.connectivity input=airtraffic output=connectivity \
104 set1_where="name=JFK" set2_where="name=Heathrow" node_column=capacity
105
107 v.net, v.net.flow, v.net.bridge
108
110 Daniel Bundala, Google Summer of Code 2009, Student
111 Wolf Bergenheim, Mentor
112
114 Available at: v.net.connectivity source code (history)
115 Main index | Vector index | Topics index | Keywords index | Graphical
117 index | Full index
118 © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual
120GRASS 7.8.2 v.net.connectivity(1)