Difference between revisions of "Vector network analysis"

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GRASS provides support for vector network analysis using the [http://trac.osgeo.org/grass/browser/grass/trunk/lib/vector/dglib/ DGlib] Directed Graph Library.
 
GRASS provides support for vector network analysis using the [http://trac.osgeo.org/grass/browser/grass/trunk/lib/vector/dglib/ DGlib] Directed Graph Library.
  
The following algorithms are implemented:
+
The following algorithms are implemented (GRASS 6.5+):
  
* Vector maintenance: {{cmd|v.net}}
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* Vector maintenance: {{cmd|v.net|version=70}}
* Shortest path: {{cmd|d.path}} and {{cmd|v.net.path}}
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* Shortest path: {{cmd|d.path|version=64}} and {{cmd|v.net.path|version=70}}
* Traveling salesman (round trip): {{cmd|v.net.salesman}}
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* Shortest path between all pairs of nodes {{cmd|v.net.allpairs|version=70}}
* Allocation of sources (create subnetworks, e.g. police station zones): {{cmd|v.net.alloc}}
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* Allocation of sources (create subnetworks, e.g. police station zones): {{cmd|v.net.alloc|version=70}}
* Minimum Steiner trees (star-like connections, e.g. broadband cable connections): {{cmd|v.net.steiner}}
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* Iso-distances (from centers): {{cmd|v.net.iso|version=70}}
* Iso-distances (from centers): {{cmd|v.net.iso}}
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* Computes bridges and articulation points: {{cmd|v.net.bridge|version=70}}
 +
* Computes degree, centrality, betweeness, closeness and eigenvector centrality measures: {{cmd|v.net.centrality|version=70}}
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* Computes strongly and weakly connected components: {{cmd|v.net.components|version=70}}
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* Computes vertex connectivity between two sets of nodes: {{cmd|v.net.connectivity|version=70}}
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* Computes shortest distance via the network between the given sets of features: {{cmd|v.net.distance|version=70}}
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* Computes the maximum flow between two sets of nodes: {{cmd|v.net.flow|version=70}}
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* Computes minimum spanning tree: {{cmd|v.net.spanningtree|version=70}}
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* Minimum Steiner trees (star-like connections, e.g. broadband cable connections): {{cmd|v.net.steiner|version=70}}
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* Finds shortest path using timetables: {{cmd|v.net.timetable|version=70}}
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* Traveling salesman (round trip): {{cmd|v.net.salesman|version=70}}
  
 
Vector directions are defined by the digitizing direction (a-->--b). You can navigate either omnidirectionally or differently in each directions as both directions are supported. Network modules provide parameters to assign attribute columns to the forward and backward direction. To see how a vector is directed, use the "display" parameter of  {{cmd|d.vect}} (set display=dir).
 
Vector directions are defined by the digitizing direction (a-->--b). You can navigate either omnidirectionally or differently in each directions as both directions are supported. Network modules provide parameters to assign attribute columns to the forward and backward direction. To see how a vector is directed, use the "display" parameter of  {{cmd|d.vect}} (set display=dir).

Revision as of 11:48, 10 April 2010

Vector network analysis

GRASS provides support for vector network analysis using the DGlib Directed Graph Library.

The following algorithms are implemented (GRASS 6.5+):

Vector directions are defined by the digitizing direction (a-->--b). You can navigate either omnidirectionally or differently in each directions as both directions are supported. Network modules provide parameters to assign attribute columns to the forward and backward direction. To see how a vector is directed, use the "display" parameter of d.vect (set display=dir).

  • see the vectorintro "vector map processing and network analysis" help page

Shortest path routing

New ideas

Screenshots


v.net.iso - Split net to bands between cost isolines (direction from centre). Costs of centre node are used in calculation.


v.net.alloc - Allocates subnets for nearest centres (direction from centre). Costs of centre node are used in calculation.


d.path - Find shortest path for selected starting and ending node.

See also