.TH v.net.allpairs 1grass "" "GRASS 7.6.0" "Grass User's Manual"
.SH NAME
\fI\fBv.net.allpairs\fR\fR  \- Computes the shortest path between all pairs of nodes in the network.
.SH KEYWORDS
vector, network, shortest path
.SH SYNOPSIS
\fBv.net.allpairs\fR
.br
\fBv.net.allpairs \-\-help\fR
.br
\fBv.net.allpairs\fR [\-\fBg\fR] \fBinput\fR=\fIname\fR \fBoutput\fR=\fIname\fR  [\fBarc_layer\fR=\fIstring\fR]   [\fBnode_layer\fR=\fIstring\fR]   [\fBcats\fR=\fIrange\fR]   [\fBwhere\fR=\fIsql_query\fR]   [\fBarc_column\fR=\fIname\fR]   [\fBarc_backward_column\fR=\fIname\fR]   [\fBnode_column\fR=\fIstring\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-g\fR" 4m
.br
Use geodesic calculation for longitude\-latitude locations
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of input vector map
.br
Or data source for direct OGR access
.IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name for output vector map
.IP "\fBarc_layer\fR=\fIstring\fR" 4m
.br
Arc layer
.br
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
.br
Default: \fI1\fR
.IP "\fBnode_layer\fR=\fIstring\fR" 4m
.br
Node layer
.br
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
.br
Default: \fI2\fR
.IP "\fBcats\fR=\fIrange\fR" 4m
.br
Category values
.br
Example: 1,3,7\-9,13
.IP "\fBwhere\fR=\fIsql_query\fR" 4m
.br
WHERE conditions of SQL statement without \(cqwhere\(cq keyword
.br
Example: income < 1000 and population >= 10000
.IP "\fBarc_column\fR=\fIname\fR" 4m
.br
Arc forward/both direction(s) cost column (number)
.IP "\fBarc_backward_column\fR=\fIname\fR" 4m
.br
Arc backward direction cost column (number)
.IP "\fBnode_column\fR=\fIstring\fR" 4m
.br
Node cost column (number)
.SH DESCRIPTION
\fIv.net.allpairs\fR computes the shortest path between each selected
node and all other selected nodes. The output is a vector with the
selected nodes and the shortest paths.
.SH NOTES
An attribute table is created and linked to layer \fIarc_layer\fR. The
table contains four columns: \fIcat\fR, \fIfrom_cat\fR,
\fIto_cat\fR, \fIcost\fR.
Each \fIcat\fR entry denotes the category of the shortest path from
the node with category \fIfrom_cat\fR to the node with category
\fIto_cat\fR. If points are specified by \fBcats, layer\fR or
\fBwhere\fR parameters then the table is filled only for the selected
points.
.br
If \fBarc_backward_column\fR is not given then then the same costs are used for
forward and backward arcs.
.SH EXAMPLE
Find shortest path along roads from selected archsites (Spearfish sample
dataset):
.br
.nf
\fC
# prepare network: connect archsites to roads with threshold 200
v.net input=roads@PERMANENT points=archsites@PERMANENT \(rs
output=roads_net operation=connect thresh=200
# verify result
v.category input=roads_net option=report
# only lines should have a category in layer 1
# only points should have a category in layer 2
# shortest path between all points with categories 1 \- 5 in layer 2
v.net.allpairs input=roads_net cats=1\-5 out=roads_net_all
v.db.select roads_net_all
\fR
.fi
Result in matrix form:
.br
.nf
\fC
from\(rsto	1		3		4		5
1	0		18820.386	17206.651	17373.274
3	18820.386	0		1739.079	9040.575
4	17206.651	1739.079	0		7426.84
5	17373.274	9040.575	7426.84		0
\fR
.fi
.SH SEE ALSO
\fI
v.net.path,
v.net.distance
\fR
.SH AUTHORS
Daniel Bundala, Google Summer of Code 2009, Student
.br
Wolf Bergenheim, Mentor
.br
Markus Metz
.PP
\fILast changed: $Date: 2014\-12\-24 15:11:14 +0100 (Wed, 24 Dec 2014) $\fR
.SH SOURCE CODE
.PP
Available at: v.net.allpairs source code (history)
.PP
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.PP
© 2003\-2019
GRASS Development Team,
GRASS GIS 7.6.0 Reference Manual