pgr_edgeDisjointPaths - pgRouting Manual (3.2)
pgr_edgeDisjointPaths
pgr_edgeDisjointPaths
- Calculates edge disjoint paths between two groups of vertices.
Availability
-
Version 3.2.0
-
New proposed function:
-
pgr_edgeDisjointPaths(Combinations)
-
-
-
Version 3.0.0
-
Official function
-
-
Version 2.5.0
-
Proposed function
-
-
Version 2.3.0
-
New Experimental function
-
Description
Calculates the edge disjoint paths between two groups of vertices. Utilizes underlying maximum flow algorithms to calculate the paths.
- The main characterics are:
-
-
Calculates the edge disjoint paths between any two groups of vertices.
-
Returns EMPTY SET when source and destination are the same, or cannot be reached.
-
The graph can be directed or undirected.
-
One to many, many to one, many to many versions are also supported.
-
Uses pgr_boykovKolmogorov to calculate the paths.
-
Signatures
Summary
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vid)
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vid [, directed])
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vids [, directed])
pgr_edgeDisjointPaths(Edges SQL, start_vids, end_vid [, directed])
pgr_edgeDisjointPaths(Edges SQL, start_vids, end_vids [, directed])
pgr_edgeDisjointPaths(Edges SQL, Combinations SQL [, directed]) -- Proposed on v3.2
RETURNS SET OF (seq, path_id, path_seq, [start_vid,] [end_vid,] node, edge, cost, agg_cost)
OR EMPTY SET
Using defaults
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vid)
RETURNS SET OF (seq, path_id, path_seq, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(3\) to vertex \(5\) on a directed graph
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
3, 5
);
seq path_id path_seq node edge cost agg_cost
-----+---------+----------+------+------+------+----------
1 1 1 3 2 1 0
2 1 2 2 4 1 1
3 1 3 5 -1 0 2
4 2 1 3 5 1 0
5 2 2 6 8 1 1
6 2 3 5 -1 0 2
(6 rows)
One to One
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vid, directed)
RETURNS SET OF (seq, path_id, path_seq, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(3\) to vertex \(5\) on an undirected graph
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
3, 5,
directed := false
);
seq path_id path_seq node edge cost agg_cost
-----+---------+----------+------+------+------+----------
1 1 1 3 2 1 0
2 1 2 2 4 1 1
3 1 3 5 -1 0 2
4 2 1 3 3 -1 0
5 2 2 4 16 1 -1
6 2 3 9 9 1 0
7 2 4 6 8 1 1
8 2 5 5 -1 0 2
9 3 1 3 5 1 0
10 3 2 6 11 1 1
11 3 3 11 12 -1 2
12 3 4 10 10 1 1
13 3 5 5 -1 0 2
(13 rows)
One to Many
pgr_edgeDisjointPaths(Edges SQL, start_vid, end_vids, directed)
RETURNS SET OF (seq, path_id, path_seq, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(3\) to vertices \(\{4, 5, 10\}\) on a directed graph
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
3, ARRAY[4, 5, 10]
);
seq path_id path_seq end_vid node edge cost agg_cost
-----+---------+----------+---------+------+------+------+----------
1 1 1 4 3 5 1 0
2 1 2 4 6 9 1 1
3 1 3 4 9 16 1 2
4 1 4 4 4 -1 0 3
5 2 1 5 3 2 1 0
6 2 2 5 2 4 1 1
7 2 3 5 5 -1 0 2
8 3 1 5 3 5 1 0
9 3 2 5 6 8 1 1
10 3 3 5 5 -1 0 2
11 4 1 10 3 2 1 0
12 4 2 10 2 4 1 1
13 4 3 10 5 10 1 2
14 4 4 10 10 -1 0 3
(14 rows)
Many to One
pgr_edgeDisjointPaths(Edges SQL, start_vids, end_vid, directed)
RETURNS SET OF (seq, path_id, path_seq, start_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertices \(\{3, 6\}\) to vertex \(5\) on a directed graph
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[3, 6], 5
);
seq path_id path_seq start_vid node edge cost agg_cost
-----+---------+----------+-----------+------+------+------+----------
1 1 1 0 3 2 1 0
2 1 2 0 2 4 1 1
3 1 3 0 5 -1 0 2
4 2 1 1 3 5 1 0
5 2 2 1 6 8 1 1
6 2 3 1 5 -1 0 2
7 3 1 2 6 8 1 0
8 3 2 2 5 -1 0 1
9 4 1 3 6 9 1 0
10 4 2 3 9 16 1 1
11 4 3 3 4 3 1 2
12 4 4 3 3 2 1 3
13 4 5 3 2 4 1 4
14 4 6 3 5 -1 0 5
(14 rows)
Many to Many
pgr_edgeDisjointPaths(Edges SQL, start_vids, end_vids, directed)
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertices \(\{3, 6\}\) to vertices \(\{4, 5, 10\}\) on a directed graph
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[3, 6], ARRAY[4, 5, 10]
);
seq path_id path_seq start_vid end_vid node edge cost agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------
1 1 1 0 4 3 5 1 0
2 1 2 0 4 6 9 1 1
3 1 3 0 4 9 16 1 2
4 1 4 0 4 4 -1 0 3
5 2 1 1 5 3 2 1 0
6 2 2 1 5 2 4 1 1
7 2 3 1 5 5 -1 0 2
8 3 1 2 5 3 5 1 0
9 3 2 2 5 6 8 1 1
10 3 3 2 5 5 -1 0 2
11 4 1 3 10 3 2 1 0
12 4 2 3 10 2 4 1 1
13 4 3 3 10 5 10 1 2
14 4 4 3 10 10 -1 0 3
15 5 1 4 4 6 9 1 0
16 5 2 4 4 9 16 1 1
17 5 3 4 4 4 -1 0 2
18 6 1 5 5 6 8 1 0
19 6 2 5 5 5 -1 0 1
20 7 1 6 5 6 9 1 0
21 7 2 6 5 9 16 1 1
22 7 3 6 5 4 3 1 2
23 7 4 6 5 3 2 1 3
24 7 5 6 5 2 4 1 4
25 7 6 6 5 5 -1 0 5
26 8 1 7 10 6 8 1 0
27 8 2 7 10 5 10 1 1
28 8 3 7 10 10 -1 0 2
(28 rows)
Combinations
pgr_edgeDisjointPaths(Edges SQL, Combinations SQL, directed)
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
Using a combinations table, equivalent to calculating result from vertices \(\{3, 6\}\) to vertices \(\{4, 5, 10\}\) on a directed graph.
SELECT * FROM pgr_edgeDisjointPaths(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
'SELECT * FROM ( VALUES (3, 4), (6, 5), (3, 10) ) AS t(source, target)'
);
seq path_id path_seq start_vid end_vid node edge cost agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------
1 1 1 0 4 3 5 1 0
2 1 2 0 4 6 9 1 1
3 1 3 0 4 9 16 1 2
4 1 4 0 4 4 -1 0 3
5 2 1 1 5 3 2 1 0
6 2 2 1 5 2 4 1 1
7 2 3 1 5 5 -1 0 2
8 3 1 2 5 3 5 1 0
9 3 2 2 5 6 8 1 1
10 3 3 2 5 5 -1 0 2
11 4 1 3 10 3 2 1 0
12 4 2 3 10 2 4 1 1
13 4 3 3 10 5 10 1 2
14 4 4 3 10 10 -1 0 3
15 5 1 4 4 6 9 1 0
16 5 2 4 4 9 16 1 1
17 5 3 4 4 4 -1 0 2
18 6 1 5 5 6 8 1 0
19 6 2 5 5 5 -1 0 1
20 7 1 6 5 6 9 1 0
21 7 2 6 5 9 16 1 1
22 7 3 6 5 4 3 1 2
23 7 4 6 5 3 2 1 3
24 7 5 6 5 2 4 1 4
25 7 6 6 5 5 -1 0 5
26 8 1 7 10 6 8 1 0
27 8 2 7 10 5 10 1 1
28 8 3 7 10 10 -1 0 2
(28 rows)
Parameters
|
Parameter |
Type |
Default |
Description |
|---|---|---|---|
|
Edges SQL |
|
Edges query as described below |
|
|
Combinations SQL |
|
Combinations query as described below |
|
|
start_vid |
|
Identifier of the starting vertex of the path. |
|
|
start_vids |
|
Array of identifiers of starting vertices. |
|
|
end_vid |
|
Identifier of the ending vertex of the path. |
|
|
end_vids |
|
Array of identifiers of ending vertices. |
|
|
directed |
|
|
|
Inner queries
Edges query
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
id |
|
Identifier of the edge. |
|
|
source |
|
Identifier of the first end point vertex of the edge. |
|
|
target |
|
Identifier of the second end point vertex of the edge. |
|
|
cost |
|
Weight of the edge (source, target)
|
|
|
reverse_cost |
|
-1 |
Weight of the edge (target, source) ,
|
Where:
- ANY-INTEGER :
-
SMALLINT, INTEGER, BIGINT
- ANY-NUMERICAL :
-
SMALLINT, INTEGER, BIGINT, REAL, FLOAT
Combinations query
- Combinations SQL :
-
an SQL query which should return a set of rows with the following columns:
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
source |
|
Identifier of the first end point vertex of the edge. |
|
|
target |
|
Identifier of the second end point vertex of the edge. |
Where:
- ANY-INTEGER :
-
SMALLINT, INTEGER, BIGINT
The function aggregates the sources and the targets, removes the duplicates, and then it calculates the result from the resultant source vertices to the target vertices.
Return Columns
Returns set of
(seq,
path_id,
path_seq
[,
start_vid]
[,
end_vid],
node,
edge,
cost,
agg_cost)
|
Column |
Type |
Description |
|---|---|---|
|
seq |
|
Sequential value starting from 1 . |
|
path_id |
|
Path identifier. Has value
1
for the first of a path. Used when there are multiple paths for the same
|
|
path_seq |
|
Relative position in the path. Has value 1 for the beginning of a path. |
|
start_vid |
|
Identifier of the starting vertex. Returned when multiple starting vetrices are in the query. |
|
end_vid |
|
Identifier of the ending vertex. Returned when multiple ending vertices are in the query. |
|
node |
|
Identifier of the node in the path from
|
|
edge |
|
Identifier of the edge used to go from
|
|
cost |
|
Cost to traverse from
|
|
agg_cost |
|
Aggregate cost from
|
See Also
Indices and tables