pgr_dijkstraVia - Proposed - pgRouting Manual (3.4)
pgr_dijkstraVia
- Proposed
pgr_dijkstraVia
- Route that goes through a list of vertices.
Warning
Proposed functions for next mayor release.
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They are not officially in the current release.
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They will likely officially be part of the next mayor release:
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The functions make use of ANY-INTEGER and ANY-NUMERICAL
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Name might not change. (But still can)
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Signature might not change. (But still can)
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Functionality might not change. (But still can)
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pgTap tests have being done. But might need more.
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Documentation might need refinement.
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Availability
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Version 2.2.0
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New proposed function
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Description
Given a list of vertices and a graph, this function is equivalent to finding the shortest path between \(vertex_i\) and \(vertex_{i+1}\) for all \(i < size\_of(via\;vertices)\) .
- Route :
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is a sequence of paths.
- Path :
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is a section of the route.
Signatures
One Via
[directed,
strict,
U_turn_on_edge]
(seq,
path_id,
path_seq,
start_vid,
end_vid,
node,
edge,
cost,
agg_cost,
route_agg_cost)
- Example :
-
Find the route that visits the vertices \(\{5, 1, 8\}\) in that order on an directed graph.
SELECT * FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 1, 8]);
seq path_id path_seq start_vid end_vid node edge cost agg_cost route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 1 1 5 1 5 1 1 0 0
2 1 2 5 1 6 4 1 1 1
3 1 3 5 1 7 7 1 2 2
4 1 4 5 1 3 6 1 3 3
5 1 5 5 1 1 -1 0 4 4
6 2 1 1 8 1 6 1 0 4
7 2 2 1 8 3 7 1 1 5
8 2 3 1 8 7 10 1 2 6
9 2 4 1 8 8 -2 0 3 7
(9 rows)
Parameters
|
Parameter |
Type |
Default |
Description |
|---|---|---|---|
|
|
SQL query as described. |
||
|
via vertices |
|
Array of ordered vertices identifiers that are going to be visited. |
Where:
- ANY-INTEGER :
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SMALLINT, INTEGER, BIGINT
Optional parameters
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
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|
|
|
Via optional parameters
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Parameter |
Type |
Default |
Description |
|---|---|---|---|
|
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Inner Queries
Edges SQL
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
|
ANY-INTEGER |
Identifier of the edge. |
|
|
|
ANY-INTEGER |
Identifier of the first end point vertex of the edge. |
|
|
|
ANY-INTEGER |
Identifier of the second end point vertex of the edge. |
|
|
|
ANY-NUMERICAL |
Weight of the edge (
|
|
|
|
ANY-NUMERICAL |
-1 |
Weight of the edge (
|
Where:
- ANY-INTEGER :
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SMALLINT,INTEGER,BIGINT - ANY-NUMERICAL :
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SMALLINT,INTEGER,BIGINT,REAL,FLOAT
Result Columns
|
Column |
Type |
Description |
|---|---|---|
|
|
|
Sequential value starting from 1 . |
|
|
|
Identifier of a path. Has value 1 for the first path. |
|
|
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Relative position in the path. Has value 1 for the beginning of a path. |
|
|
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Identifier of the starting vertex of the path. |
|
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Identifier of the ending vertex of the path. |
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Identifier of the node in the path from
|
|
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Identifier of the edge used to go from
|
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Cost to traverse from
|
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Aggregate cost from
|
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|
|
Total cost from
|
Additional Examples
All this examples are about the route that visits the vertices \(\{5, 7, 1, 8, 15\}\) in that order on a directed graph.
The main query
SELECT * FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15]);
seq path_id path_seq start_vid end_vid node edge cost agg_cost route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 1 1 5 7 5 1 1 0 0
2 1 2 5 7 6 4 1 1 1
3 1 3 5 7 7 -1 0 2 2
4 2 1 7 1 7 7 1 0 2
5 2 2 7 1 3 6 1 1 3
6 2 3 7 1 1 -1 0 2 4
7 3 1 1 8 1 6 1 0 4
8 3 2 1 8 3 7 1 1 5
9 3 3 1 8 7 10 1 2 6
10 3 4 1 8 8 -1 0 3 7
11 4 1 8 15 8 12 1 0 7
12 4 2 8 15 12 13 1 1 8
13 4 3 8 15 17 15 1 2 9
14 4 4 8 15 16 16 1 3 10
15 4 5 8 15 15 -2 0 4 11
(15 rows)
Aggregate cost of the third path.
SELECT agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge <0;
agg_cost
----------
3
(1 row)
Route’s aggregate cost of the route at the end of the third path.
SELECT route_agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge < 0;
route_agg_cost
----------------
7
(1 row)
Nodes visited in the route.
SELECT row_number() over () as node_seq, node
FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE edge <> -1 ORDER BY seq;
node_seq node
----------+------
1 5
2 6
3 7
4 3
5 1
6 3
7 7
8 8
9 12
10 17
11 16
12 15
(12 rows)
The aggregate costs of the route when the visited vertices are reached.
SELECT path_id, route_agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE edge < 0;
path_id route_agg_cost
---------+----------------
1 2
2 4
3 7
4 11
(4 rows)
Status of "passes in front" or "visits" of the nodes.
SELECT seq, route_agg_cost, node, agg_cost ,
CASE WHEN edge = -1 THEN 'visits'
ELSE 'passes in front'
END as status
FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE agg_cost <> 0 or seq = 1;
seq route_agg_cost node agg_cost status
-----+----------------+------+----------+-----------------
1 0 5 0 passes in front
2 1 6 1 passes in front
3 2 7 2 visits
5 3 3 1 passes in front
6 4 1 2 visits
8 5 3 1 passes in front
9 6 7 2 passes in front
10 7 8 3 visits
12 8 12 1 passes in front
13 9 17 2 passes in front
14 10 16 3 passes in front
15 11 15 4 passes in front
(12 rows)
See Also
-
Sample Data network.
Indices and tables