pgr_chinesePostmanCost - Experimental¶
pgr_chinesePostmanCost
— Calculates the minimum costs of a circuit path which
contains every edge in a directed graph and starts and ends on the same vertex.
Warning
Possible server crash
- These functions might create a server crash
Warning
Experimental functions
- They are not officially of the current release.
- They likely will not be officially be part of the next release:
- The functions might not make use of ANY-INTEGER and ANY-NUMERICAL
- Name might change.
- Signature might change.
- Functionality might change.
- pgTap tests might be missing.
- Might need c/c++ coding.
- May lack documentation.
- Documentation if any might need to be rewritten.
- Documentation examples might need to be automatically generated.
- Might need a lot of feedback from the comunity.
- Might depend on a proposed function of pgRouting
- Might depend on a deprecated function of pgRouting
Availability
- Version 3.0.0
- New experimental function
Support
Description¶
The main characteristics are:
- Process is done only on edges with positive costs.
- Running time: \(O(E * (E + V * logV))\)
- Graph must be connected.
- [TBD] Return value when the graph if disconnected
Signatures¶
pgr_chinesePostmanCost(edges_sql)
RETURNS FLOAT
Example: |
---|
SELECT * FROM pgr_chinesePostmanCost(
'SELECT id,
source, target,
cost, reverse_cost FROM edge_table where id < 17'
);
pgr_chinesepostmancost
------------------------
34
(1 row)
Parameters¶
Column | Type | Default | Description |
---|---|---|---|
edges_sql | TEXT |
The edges SQL query as described in Inner query. |
Inner query¶
An Edges SQL that represents a directed graph with the following columns
Column | Type | Default | Description |
---|---|---|---|
id | ANY-INTEGER |
Identifier of the edge. | |
source | ANY-INTEGER |
Identifier of the first end point vertex of the edge. | |
target | ANY-INTEGER |
Identifier of the second end point vertex of the edge. | |
cost | ANY-NUMERICAL |
Weight of the edge (source, target)
|
|
reverse_cost | ANY-NUMERICAL |
-1 | Weight of the edge (target, source),
|
Where:
ANY-INTEGER: | SMALLINT, INTEGER, BIGINT |
---|---|
ANY-NUMERICAL: | SMALLINT, INTEGER, BIGINT, REAL, FLOAT |
Result Columns¶
Type | Description |
---|---|
FLOAT |
Minimum costs of a circuit path. |
See Also¶
Indices and tables