pgr_withPointsCostMatrix - proposed¶
Name¶
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
These are 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.
Signature Summary¶
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vids)
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.
Signatures¶
Minimal Signature¶
- 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: |
---|
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: | returning a symmetrical cost matrix |
---|
- Using the default side value on the points_sql query
- Using an undirected graph
- 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)
Description of the Signatures¶
Description of the edges_sql query¶
edges_sql: | an SQL query, which should return a set of rows 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 |
|
|
reverse_cost | ANY-NUMERICAL | -1 |
|
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 |
|
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 |
|
Where:
ANY-INTEGER: | smallint, int, bigint |
---|---|
ANY-NUMERICAL: | smallint, int, bigint, real, float |
Description of the parameters of the signatures¶
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 |
|
Description of the return values¶
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 of the shortest path from start_vid to end_vid. |
Examples¶
Example: | Use with tsp |
---|
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¶
- withPoints - Family of functions
- Cost Matrix
- Traveling Sales Person
- sampledata network.
Indices and tables