pgr_bdAstar
— Returns the shortest path using Bidirectional A* algorithm.
Availability:
Support
The main characteristics are:
directed
flag is missing.directed
flag is set to truestart_vid
(if exists)end_vid
agg_cost
from \(v\) to \(u\) is \(\infty\)agg_cost
from v to u is \(0\)start_vid
and end_vid
in the result is used to distinguish to which path it belongs.Summary
pgr_bdAstar(edges_sql, from_vid, to_vid, [, directed] [, heuristic] [, factor] [, epsilon])
pgr_bdAstar(edges_sql, from_vid, to_vids [, directed] [, heuristic] [, factor] [, epsilon])
pgr_bdAstar(edges_sql, from_vids, to_vid [, directed] [, heuristic] [, factor] [, epsilon])
pgr_bdAstar(edges_sql, from_vids, to_vids [, directed] [, heuristic] [, factor] [, epsilon])
RETURNS SET OF (seq, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
OR EMPTY SET
Optional parameters are named parameters and have a default value.
Using defaults
pgr_bdAstar(edges_sql, start_vid, end_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
Example: | From vertex \(2\) to vertex \(3\) on a directed graph |
---|
SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | 8 | 1 | 1
3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 9 | 16 | 1 | 3
5 | 5 | 4 | 3 | 1 | 4
6 | 6 | 3 | -1 | 0 | 5
(6 rows)
pgr_bdAstar(edges_sql, from_vid, to_vid, [, directed] [, heuristic] [, factor] [, epsilon])
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
Example: | From vertex \(2\) to vertex \(3\) on a directed graph using heuristic \(2\) |
---|
SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, 3,
true, heuristic := 2
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | 8 | 1 | 1
3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 9 | 16 | 1 | 3
5 | 5 | 4 | 3 | 1 | 4
6 | 6 | 3 | -1 | 0 | 5
(6 rows)
pgr_bdAstar(edges_sql, from_vid, to_vids [, directed] [, heuristic] [, factor] [, epsilon])
RETURNS SET OF (seq, path_seq, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
Example: | From vertex \(2\) to vertices \(\{3, 11\}\) on a directed graph using heuristic \(3\) and factor \(3.5\) |
---|
SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, ARRAY[3, 11],
heuristic := 3, factor := 3.5
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 3 | 2 | 4 | 1 | 0
2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 3 | 9 | 16 | 1 | 3
5 | 5 | 3 | 4 | 3 | 1 | 4
6 | 6 | 3 | 3 | -1 | 0 | 5
7 | 1 | 11 | 2 | 4 | 1 | 0
8 | 2 | 11 | 5 | 8 | 1 | 1
9 | 3 | 11 | 6 | 11 | 1 | 2
10 | 4 | 11 | 11 | -1 | 0 | 3
(10 rows)
pgr_bdAstar(edges_sql, from_vids, to_vid [, directed] [, heuristic] [, factor] [, epsilon])
RETURNS SET OF (seq, path_seq, start_vid, node, edge, cost, agg_cost)
OR EMPTY SET
Example: | From vertices \(\{2, 7\}\) to vertex \(3\) on an undirected graph using heuristic \(4\) |
---|
SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
ARRAY[2, 7], 3,
false, heuristic := 4
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+-----------+------+------+------+----------
1 | 1 | 2 | 2 | 2 | 1 | 0
2 | 2 | 2 | 3 | -1 | 0 | 1
3 | 1 | 7 | 7 | 6 | 1 | 0
4 | 2 | 7 | 8 | 7 | 1 | 1
5 | 3 | 7 | 5 | 8 | 1 | 2
6 | 4 | 7 | 6 | 5 | 1 | 3
7 | 5 | 7 | 3 | -1 | 0 | 4
(7 rows)
pgr_bdAstar(edges_sql, from_vids, to_vids [, directed] [, heuristic] [, factor] [, epsilon])
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
Example: | From vertices \(\{2, 7\}\) to vertices \(\{3, 11\}\) on a directed graph using factor \(0.5\) |
---|
SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
ARRAY[2, 7], ARRAY[3, 11],
factor := 0.5
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+-----------+---------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 4 | 1 | 0
2 | 2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 2 | 3 | 6 | 9 | 1 | 2
4 | 4 | 2 | 3 | 9 | 16 | 1 | 3
5 | 5 | 2 | 3 | 4 | 3 | 1 | 4
6 | 6 | 2 | 3 | 3 | -1 | 0 | 5
7 | 1 | 2 | 11 | 2 | 4 | 1 | 0
8 | 2 | 2 | 11 | 5 | 8 | 1 | 1
9 | 3 | 2 | 11 | 6 | 11 | 1 | 2
10 | 4 | 2 | 11 | 11 | -1 | 0 | 3
11 | 1 | 7 | 3 | 7 | 6 | 1 | 0
12 | 2 | 7 | 3 | 8 | 7 | 1 | 1
13 | 3 | 7 | 3 | 5 | 8 | 1 | 2
14 | 4 | 7 | 3 | 6 | 9 | 1 | 3
15 | 5 | 7 | 3 | 9 | 16 | 1 | 4
16 | 6 | 7 | 3 | 4 | 3 | 1 | 5
17 | 7 | 7 | 3 | 3 | -1 | 0 | 6
18 | 1 | 7 | 11 | 7 | 6 | 1 | 0
19 | 2 | 7 | 11 | 8 | 7 | 1 | 1
20 | 3 | 7 | 11 | 5 | 8 | 1 | 2
21 | 4 | 7 | 11 | 6 | 11 | 1 | 3
22 | 5 | 7 | 11 | 11 | -1 | 0 | 4
(22 rows)
Parameter | Type | Description |
---|---|---|
edges_sql | TEXT |
edges_sql inner query. |
from_vid | ANY-INTEGER |
Starting vertex identifier. Parameter in: |
from_vids | ARRAY[ANY-INTEGER] |
Array of starting vertices identifiers. Parameter in: |
to_vid | ANY-INTEGER |
Ending vertex identifier. Parameter in: |
to_vids | ARRAY[ANY-INTEGER] |
Array of ending vertices identifiers. Parameter in: |
Parameter | Type | Default | Description |
---|---|---|---|
directed | BOOLEAN |
true |
|
heuristic | INTEGER |
5 |
Heuristic number. Current valid values 0~5. Default
|
factor | FLOAT |
1 |
For units manipulation. \(factor > 0\). See Factor |
epsilon | FLOAT |
1 |
For less restricted results. \(epsilon >= 1\). |
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 |
Weight of the edge (source, target)
|
|
reverse_cost | ANY-NUMERICAL |
-1 | Weight of the edge (target, source),
|
x1 | ANY-NUMERICAL |
X coordinate of source vertex. | |
y1 | ANY-NUMERICAL |
Y coordinate of source vertex. | |
x2 | ANY-NUMERICAL |
X coordinate of target vertex. | |
y2 | ANY-NUMERICAL |
Y coordinate of target vertex. |
Where:
ANY-INTEGER: | SMALLINT, INTEGER, BIGINT |
---|---|
ANY-NUMERICAL: | SMALLINT, INTEGER, BIGINT, REAL, FLOAT |
Returns set of (seq, path_id, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
Column | Type | Description |
---|---|---|
seq | INT |
Sequential value starting from 1. |
path_id | INT |
Path identifier. Has value 1 for the first of a path. Used when there are multiple paths for the same start_vid to end_vid combination. |
path_seq | INT |
Relative position in the path. Has value 1 for the beginning of a path. |
start_vid | BIGINT |
Identifier of the starting vertex. Returned when multiple starting vetrices are in the query. |
end_vid | BIGINT |
Identifier of the ending vertex. Returned when multiple ending vertices are in the query. |
node | BIGINT |
Identifier of the node in the path from start_vid to end_vid . |
edge | BIGINT |
Identifier of the edge used to go from node to the next node in the path sequence. -1 for the last node of the path. |
cost | FLOAT |
Cost to traverse from node using edge to the next node in the path sequence. |
agg_cost | FLOAT |
Aggregate cost from start_v to node . |