---
name: "v.net.allpairs"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/v.net.allpairs"
---

# v.net.allpairs(1grass)

Computes the shortest path between all pairs of nodes in the network.

## NAME

**v.net.allpairs**  - Computes the shortest path between all pairs of nodes in the network.

## KEYWORDS

vector, network, shortest path

## SYNOPSIS

**v.net.allpairs**\
 **v.net.allpairs --help**\
 **v.net.allpairs** \[-**g**\] **input**=*name* **output**=*name*  \[**arc\_layer**=*string*\]   \[**node\_layer**=*string*\]   \[**cats**=*range*\]   \[**where**=*sql\_query*\]   \[**arc\_column**=*name*\]   \[**arc\_backward\_column**=*name*\]   \[**node\_column**=*string*\]   \[--**overwrite**\]  \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-g**

  Use geodesic calculation for longitude-latitude projects

- **--overwrite**

  Allow output files to overwrite existing files

- **--help**

  Print usage summary

- **--verbose**

  Verbose module output

- **--quiet**

  Quiet module output

- **--ui**

  Force launching GUI dialog

### Parameters:

- **input**=*name* **\[required\]**

  Name of input vector map\
   Or data source for direct OGR access

- **output**=*name* **\[required\]**

  Name for output vector map

- **arc\_layer**=*string*

  Arc layer\
   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.\
   Default: *1*

- **node\_layer**=*string*

  Node layer\
   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.\
   Default: *2*

- **cats**=*range*

  Category values\
   Example: 1,3,7-9,13

- **where**=*sql\_query*

  WHERE conditions of SQL statement without ’where’ keyword\
   Example: income \< 1000 and population \>= 10000

- **arc\_column**=*name*

  Arc forward/both direction(s) cost column (number)

- **arc\_backward\_column**=*name*

  Arc backward direction cost column (number)

- **node\_column**=*string*

  Node cost column (number)

## DESCRIPTION

*v.net.allpairs* 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.

## NOTES

An attribute table is created and linked to layer *arc\_layer*. The table contains four columns: *cat*, *from\_cat*, *to\_cat*, *cost*. Each *cat* entry denotes the category of the shortest path from the node with category *from\_cat* to the node with category *to\_cat*. If points are specified by **cats, layer** or **where** parameters then the table is filled only for the selected points.\
 If **arc\_backward\_column** is not given then then the same costs are used for forward and backward arcs.

## EXAMPLE

Find shortest path along roads from selected archsites (Spearfish sample dataset):\

```
# prepare network: connect archsites to roads with threshold 200
v.net input=roads@PERMANENT points=archsites@PERMANENT \
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
```

Result in matrix form:\

```
from\to	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
```

## SEE ALSO

*v.net.path,* *v.net.distance*

## AUTHORS

Daniel Bundala, Google Summer of Code 2009, Student\
 Wolf Bergenheim, Mentor\
 Markus Metz

## SOURCE CODE

Available at: v.net.allpairs source code (history)

Accessed: Monday Feb 24 17:51:18 2025

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