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..
****************************************************************************
pgRouting Manual
Copyright(c) pgRouting Contributors
This documentation is licensed under a Creative Commons Attribution-Share
Alike 3.0 License: https://creativecommons.org/licenses/by-sa/3.0/
****************************************************************************
|
* **Supported versions:**
`Latest <https://docs.pgrouting.org/latest/en/pgr_lineGraph.html>`__
(`3.4 <https://docs.pgrouting.org/3.4/en/pgr_lineGraph.html>`__)
`3.3 <https://docs.pgrouting.org/3.3/en/pgr_lineGraph.html>`__
`3.2 <https://docs.pgrouting.org/3.2/en/pgr_lineGraph.html>`__
`3.1 <https://docs.pgrouting.org/3.1/en/pgr_lineGraph.html>`__)
`3.0 <https://docs.pgrouting.org/3.0/en/pgr_lineGraph.html>`__
* **Unsupported versions:**
`2.6 <https://docs.pgrouting.org/2.6/en/pgr_lineGraph.html>`__
`2.5 <https://docs.pgrouting.org/2.5/en/pgr_lineGraph.html>`__
``pgr_lineGraph`` - Experimental
===============================================================================
``pgr_lineGraph`` — Transforms the given graph into its corresponding edge-based
graph.
.. figure:: images/boost-inside.jpeg
:target: https://www.boost.org/libs/graph/doc/dijkstra_shortest_paths.html
Boost Graph Inside
.. include:: experimental.rst
:start-after: begin-warn-expr
:end-before: end-warn-expr
.. rubric:: Availability
* Version 2.5.0
* New **Experimental** function
Description
-------------------------------------------------------------------------------
Given a graph G, its line graph L(G) is a graph such that:
- Each vertex of L(G) represents an edge of G
- Two vertices of L(G) are adjacent if and only if their corresponding edges
share a common endpoint in G.
.. index::
single: lineGraph - Experimental on v2.5
Signatures
-------------------------------------------------------------------------------
.. admonition:: \ \
:class: signatures
| pgr_lineGraph(`Edges SQL`_, [``directed``])
| RETURNS SET OF |result-lineg|
| OR EMPTY SET
:Example: For a **directed** graph
.. literalinclude:: doc-pgr_lineGraph.queries
:start-after: -- q1
:end-before: -- q2
Parameters
-------------------------------------------------------------------------------
.. include:: pgRouting-concepts.rst
:start-after: only_edge_param_start
:end-before: only_edge_param_end
Optional parameters
...............................................................................
.. include:: dijkstra-family.rst
:start-after: dijkstra_optionals_start
:end-before: dijkstra_optionals_end
Inner Queries
-------------------------------------------------------------------------------
Edges SQL
...............................................................................
.. include:: pgRouting-concepts.rst
:start-after: basic_edges_sql_start
:end-before: basic_edges_sql_end
Result Columns
-------------------------------------------------------------------------------
RETURNS SET OF |result-lineg|
.. list-table::
:width: 81
:widths: auto
:header-rows: 1
* - Column
- Type
- Description
* - ``seq``
- ``INTEGER``
- Sequential value starting from **1**.
- Gives a local identifier for the edge
* - ``source``
- ``BIGINT``
- Identifier of the source vertex of the current edge.
* When `negative`: the source is the reverse edge in the original graph.
* - ``target``
- ``BIGINT``
- Identifier of the target vertex of the current edge.
* When `negative`: the target is the reverse edge in the original graph.
* - ``cost``
- ``FLOAT``
- Weight of the edge (``source``, ``target``).
* When `negative`: edge (``source``, ``target``) does not exist,
therefore it’s not part of the graph.
* - ``reverse_cost``
- ``FLOAT``
- Weight of the edge (``target``, ``source``).
* When `negative`: edge (``target``, ``source``) does not exist,
therefore it’s not part of the graph.
See Also
-------------------------------------------------------------------------------
* https://en.wikipedia.org/wiki/Line_graph
* The queries use the :doc:`sampledata` network.
.. rubric:: Indices and tables
* :ref:`genindex`
* :ref:`search`
|
