pgr_withPointsCostMatrix - proposed¶
pgr_withPointsCostMatrix
- Calculates the shortest path and returns only the aggregate cost of the shortest path(s) found, for the combination of points given.
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.
Availability
- Version 2.2.0
- New proposed function
- Supported versions: current(3.1) 3.0
- Unsupported versions: 2.6 2.5 2.4 2.3
Description¶
- TBD
Signatures¶
Summary
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vids [, directed] [, driving_side])
RETURNS SET OF (start_vid, end_vid, agg_cost)
Note
There is no details flag, unlike the other members of the withPoints family of functions.
Using default
- The minimal signature:
- Is for a directed graph.
- The driving side is set as b both. So arriving/departing to/from the point(s) can be in any direction.
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vid)
RETURNS SET OF (start_vid, end_vid, agg_cost)
Example: | Cost matrix for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on a directed graph |
---|
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[-1, 3, 6, -6]);
start_vid | end_vid | agg_cost
-----------+---------+----------
-6 | -1 | 1.3
-6 | 3 | 4.3
-6 | 6 | 1.3
-1 | -6 | 1.3
-1 | 3 | 5.6
-1 | 6 | 2.6
3 | -6 | 1.7
3 | -1 | 1.6
3 | 6 | 1
6 | -6 | 1.3
6 | -1 | 2.6
6 | 3 | 3
(12 rows)
Complete Signature¶
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vids,
directed:=true, driving_side:='b')
RETURNS SET OF (start_vid, end_vid, agg_cost)
Example: | Cost matrix for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on an undirected graph |
---|
- Returning a symmetrical cost matrix
- Using the default side value on the points_sql query
- Using the default driving_side value
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[-1, 3, 6, -6], directed := false);
start_vid | end_vid | agg_cost
-----------+---------+----------
-6 | -1 | 1.3
-6 | 3 | 1.7
-6 | 6 | 1.3
-1 | -6 | 1.3
-1 | 3 | 1.6
-1 | 6 | 2.6
3 | -6 | 1.7
3 | -1 | 1.6
3 | 6 | 1
6 | -6 | 1.3
6 | -1 | 2.6
6 | 3 | 1
(12 rows)
Parameters¶
Parameter | Type | Description |
---|---|---|
edges_sql | TEXT |
Edges SQL query as described above. |
points_sql | TEXT |
Points SQL query as described above. |
start_vids | ARRAY[ANY-INTEGER] |
Array of identifiers of starting vertices. When negative: is a point’s pid. |
directed | BOOLEAN |
(optional). When false the graph is considered as Undirected. Default is true which considers the graph as Directed. |
driving_side | CHAR |
|
Returns SET OF (start_vid, end_vid, agg_cost)
Column | Type | Description |
---|---|---|
start_vid | BIGINT |
Identifier of the starting vertex. |
end_vid | BIGINT |
Identifier of the ending vertex. |
agg_cost | FLOAT |
Aggregate cost from start_vid to end_vid . |
Inner query¶
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 |
Description of the Points SQL query
points_sql: | an SQL query, which should return a set of rows with the following columns: |
---|
Column | Type | Description |
---|---|---|
pid | ANY-INTEGER |
(optional) Identifier of the point.
|
edge_id | ANY-INTEGER |
Identifier of the “closest” edge to the point. |
fraction | ANY-NUMERICAL |
Value in <0,1> that indicates the relative postition from the first end point of the edge. |
side | CHAR |
(optional) Value in [‘b’, ‘r’, ‘l’, NULL] indicating if the point is:
|
Where:
ANY-INTEGER: | smallint, int, bigint |
---|---|
ANY-NUMERICAL: | smallint, int, bigint, real, float |
Additional Examples¶
Example: | pgr_TSP using pgr_withPointsCostMatrix for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on an undirected graph |
---|
SELECT * FROM pgr_TSP(
$$
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[-1, 3, 6, -6], directed := false);
$$,
randomize := false
);
seq | node | cost | agg_cost
-----+------+------+----------
1 | -6 | 1.3 | 0
2 | -1 | 1.6 | 1.3
3 | 3 | 1 | 2.9
4 | 6 | 1.3 | 3.9
5 | -6 | 0 | 5.2
(5 rows)
See Also¶
- pgr_withPoints - Proposed
- Cost Matrix - Category
- pgr_TSP
- sampledata network.
Indices and tables