v.net.iso(1)

1v.net.iso(1)                  Grass User's Manual                 v.net.iso(1)
2
3
4

NAME

6       v.net.iso  - Split net by cost isolines
7       Splits net to bands between cost isolines (direction from centre). Cen‐
8       tre node must be opened (costs >= 0). Costs of centre node are used  in
9       calculation.
10

KEYWORDS

12       vector, networking
13

SYNOPSIS

15       v.net.iso
16       v.net.iso help
17       v.net.iso   [-g]   input=name  output=name   [type=string[,string,...]]
18       [alayer=integer]     [nlayer=integer]     [afcolumn=string]     [abcol‐
19       umn=string]   [ncolumn=string]  ccats=range costs=integer[,integer,...]
20       [--overwrite]  [--verbose]  [--quiet]
21
22   Flags:
23       -g
24           Use geodesic calculation for longitude-latitude locations
25
26       --overwrite
27           Allow output files to overwrite existing files
28
29       --verbose
30           Verbose module output
31
32       --quiet
33           Quiet module output
34
35   Parameters:
36       input=name
37           Name of input vector map
38
39       output=name
40           Name for output vector map
41
42       type=string[,string,...]
43           Type
44           Arc type
45           Options: line,boundary
46           Default: line,boundary
47
48       alayer=integer
49           Layer number
50           Arc layer
51           Default: 1
52
53       nlayer=integer
54           Layer number
55           Node layer
56           Default: 2
57
58       afcolumn=string
59           Arc forward/both direction(s) cost column (number)
60
61       abcolumn=string
62           Arc backward direction cost column (number)
63
64       ncolumn=string
65           Node cost column (number)
66
67       ccats=range
68           Category values
69           Categories of centres (points on nodes) to which net will be  allo‐
70           cated. Layer for this categories is given by nlayer option.
71
72       costs=integer[,integer,...]
73           Costs for isolines
74

DESCRIPTION

76       v.net.iso  splits  net  to  bands between cost isolines (direction from
77       centre). Centre node must be opened (costs >= 0). Costs of centre  node
78       are  used  in calculation. Supported are cost assignments for both arcs
79       and nodes, and also different in both directions of a vector line.  For
80       areas cost will be calculated along boundary lines.
81

NOTES

83       Nodes must be on the isolines.
84
85       Center nodes have to be assigned to vector nodes. Nodes and arcs can be
86       closed using cost = -1.
87

EXAMPLE

89       Subdivision of a network into areas:
90       The map must contain at least one center (point) on the vector  network
91       which can be patched into with v.patch.
92       # Spearfish
93       # start node:
94       echo "591280.5|4926396.0|1" | v.in.ascii out=startnode
95       g.copy vect=roads,myroads
96       #connect point to network
97       v.net myroads points=startnode out=myroads_net op=connect thresh=200
98       g.region vect=myroads_net
99       d.mon x0
100       d.vect myroads_net
101       d.vect   myroads_net  col=red  icon=basic/triangle  fcol=green  size=12
102       layer=2
103       v.category myroads_net layer=2 op=print
104       # specify range of center cats (easier to catch all):
105       v.net.iso   input=myroads_net   output=myroads_net_iso   ccats=1-100000
106       costs=1000,2000,5000
107       v.category myroads_net_iso option=report
108       # ... reports 4 categories:
109        The network is 4 categories:
110       cat | distance from point
111       1          0 - 1000
112       2       1000 - 2000
113       3       2000 - 5000
114       4            > 5000
115        To see the result, run for example:
116       g.region n=4928200 s=4922300 w=589200 e=596500
117       d.erase
118       d.vect myroads_net_iso
119       d.vect myroads_net_iso col=blue   cats=1
120       d.vect myroads_net_iso col=green  cats=2
121       d.vect myroads_net_iso col=orange cats=3
122       d.vect myroads_net_iso col=magenta  cats=4
123       d.vect   myroads_net  col=red  icon=basic/triangle  fcol=green  size=12
124       layer=2
125
126

AUTHOR

132       Radim Blazek, ITC-Irst, Trento, Italy
133       Documentation: Markus Neteler
134
135       Last changed: $Date: 2007-08-03 14:33:14 +0200 (Fri, 03 Aug 2007) $
136
137       Full index
138
139       © 2003-2008 GRASS Development Team
140
141
142
143GRASS 6.3.0                                                       v.net.iso(1)