Topology - Family of Functions¶
The pgRouting’s topology of a network represented with a graph in form of two tables: and edge table and a vertex table.
Attributes associated to the tables help to indicate if the graph is directed or undirected, if an edge is one way on a directed graph, and depending on the final application needs, suitable topology(s) need to be created.
pgRouting suplies some functions to create a routing topology and to analyze the topology.
Additional functions to create a graph:
Additional functions to analyze a graph:
The following functions modify the database directly therefore the user must have special permissions given by the administrators to use them.
- pgr_createTopology - create a topology based on the geometry.
- pgr_createVerticesTable - reconstruct the vertices table based on the source and target information.
- pgr_analyzeGraph - to analyze the edges and vertices of the edge table.
- pgr_analyzeOneWay - to analyze directionality of the edges.
- pgr_nodeNetwork -to create nodes to a not noded edge table.
Proposed
Warning
Proposed functions for next mayor release.
- They are not officially in the current release.
- They will likely officially be part of the next mayor release:
- The functions make use of ANY-INTEGER and ANY-NUMERICAL
- Name might not change. (But still can)
- Signature might not change. (But still can)
- Functionality might not change. (But still can)
- pgTap tests have being done. But might need more.
- Documentation might need refinement.
These proposed functions do not modify the database.
- pgr_extractVertices – Proposed - Extracts vertex information based on the edge table information.