pgr_drivingDistance¶
Name¶
pgr_drivingDistance - Returns the driving distance from a start node.
Boost Graph Inside
Availability
- pgr_drivingDistance(single vertex) 2.0.0, signature change 2.1.0
- pgr_drivingDistance(multiple vertices) 2.1.0
Synopsis¶
Using Dijkstra algorithm, extracts all the nodes that have costs less than or equal to the value distance.
The edges extracted will conform the corresponding spanning tree.
Signature Summary¶
pgr_drivingDistance(edges_sql, start_vid, distance)
pgr_drivingDistance(edges_sql, start_vid, distance, directed)
pgr_drivingDistance(edges_sql, start_vids, distance, directed, equicost)
RETURNS SET OF (seq, [start_vid,] node, edge, cost, agg_cost)
Signatures¶
Minimal Use¶
pgr_drivingDistance(edges_sql, start_vid, distance)
RETURNS SET OF (seq, node, edge, cost, agg_cost)
Driving Distance From A Single Starting Vertex¶
pgr_drivingDistance(edges_sql, start_vid, distance, directed)
RETURNS SET OF (seq, node, edge, cost, agg_cost)
Driving Distance From Multiple Starting Vertices¶
pgr_drivingDistance(edges_sql, start_vids, distance, directed, equicost)
RETURNS SET OF (seq, start_vid, node, edge, cost, agg_cost)
Description of the Signatures¶
Description of the edges_sql query for dijkstra like functions¶
| 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),
|
Where:
| ANY-INTEGER: | SMALLINT, INTEGER, BIGINT |
|---|---|
| ANY-NUMERICAL: | SMALLINT, INTEGER, BIGINT, REAL, FLOAT |
Description of the parameters of the signatures¶
| Column | Type | Description |
|---|---|---|
| edges_sql | TEXT |
SQL query as described above. |
| start_vid | BIGINT |
Identifier of the starting vertex. |
| start_vids | ARRAY[ANY-INTEGER] |
Array of identifiers of starting vertices. |
| distance | FLOAT |
Upper limit for the inclusion of the node in the result. |
| directed | BOOLEAN |
(optional). When false the graph is considered as Undirected. Default is true which considers the graph as Directed. |
| equicost | BOOLEAN |
(optional). When true the node will only appear in the closest start_vid list. Default is false which resembles several calls using the single starting point signatures. Tie brakes are arbitrarely. |
Description of the return values¶
Returns set of (seq [, start_v], node, edge, cost, agg_cost)
| Column | Type | Description |
|---|---|---|
| seq | INTEGER |
Sequential value starting from 1. |
| start_vid | INTEGER |
Identifier of the starting vertex. |
| node | BIGINT |
Identifier of the node in the path within the limits from start_vid. |
| edge | BIGINT |
Identifier of the edge used to arrive to node. 0 when the node is the start_vid. |
| cost | FLOAT |
Cost to traverse edge. |
| agg_cost | FLOAT |
Aggregate cost from start_vid to node. |
Additional Examples¶
Examples for queries marked as directed with cost and reverse_cost columns¶
The examples in this section use the following Graph 1: Directed, with cost and reverse cost
/*PGR-GNU*****************************************************************
Copyright (c) 2015 pgRouting developers
Mail: project@pgrouting.org
------
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
********************************************************************PGR-GNU*/
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 2 | -1 | 0 | 0
2 | 1 | 1 | 1 | 1
3 | 5 | 4 | 1 | 1
4 | 6 | 8 | 1 | 2
5 | 8 | 7 | 1 | 2
6 | 10 | 10 | 1 | 2
7 | 7 | 6 | 1 | 3
8 | 9 | 9 | 1 | 3
9 | 11 | 12 | 1 | 3
10 | 13 | 14 | 1 | 3
(10 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
13, 3
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 13 | -1 | 0 | 0
2 | 10 | 14 | 1 | 1
3 | 5 | 10 | 1 | 2
4 | 11 | 12 | 1 | 2
5 | 2 | 4 | 1 | 3
6 | 6 | 8 | 1 | 3
7 | 8 | 7 | 1 | 3
8 | 12 | 13 | 1 | 3
(8 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,13], 3
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 5 | 4 | 1 | 1
4 | 2 | 6 | 8 | 1 | 2
5 | 2 | 8 | 7 | 1 | 2
6 | 2 | 10 | 10 | 1 | 2
7 | 2 | 7 | 6 | 1 | 3
8 | 2 | 9 | 9 | 1 | 3
9 | 2 | 11 | 12 | 1 | 3
10 | 2 | 13 | 14 | 1 | 3
11 | 13 | 13 | -1 | 0 | 0
12 | 13 | 10 | 14 | 1 | 1
13 | 13 | 5 | 10 | 1 | 2
14 | 13 | 11 | 12 | 1 | 2
15 | 13 | 2 | 4 | 1 | 3
16 | 13 | 6 | 8 | 1 | 3
17 | 13 | 8 | 7 | 1 | 3
18 | 13 | 12 | 13 | 1 | 3
(18 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,13], 3, equicost:=true
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 5 | 4 | 1 | 1
4 | 2 | 6 | 8 | 1 | 2
5 | 2 | 8 | 7 | 1 | 2
6 | 2 | 7 | 6 | 1 | 3
7 | 2 | 9 | 9 | 1 | 3
8 | 13 | 13 | -1 | 0 | 0
9 | 13 | 10 | 14 | 1 | 1
10 | 13 | 11 | 12 | 1 | 2
11 | 13 | 12 | 13 | 1 | 3
(11 rows)
Examples for queries marked as undirected with cost and reverse_cost columns¶
The examples in this section use the following Graph 2: Undirected, with cost and reverse cost
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3, false
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 2 | -1 | 0 | 0
2 | 1 | 1 | 1 | 1
3 | 3 | 2 | 1 | 1
4 | 5 | 4 | 1 | 1
5 | 4 | 3 | 1 | 2
6 | 6 | 8 | 1 | 2
7 | 8 | 7 | 1 | 2
8 | 10 | 10 | 1 | 2
9 | 7 | 6 | 1 | 3
10 | 9 | 16 | 1 | 3
11 | 11 | 12 | 1 | 3
12 | 13 | 14 | 1 | 3
(12 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
13, 3, false
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 13 | -1 | 0 | 0
2 | 10 | 14 | 1 | 1
3 | 5 | 10 | 1 | 2
4 | 11 | 12 | 1 | 2
5 | 2 | 4 | 1 | 3
6 | 6 | 8 | 1 | 3
7 | 8 | 7 | 1 | 3
8 | 12 | 13 | 1 | 3
(8 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,13], 3, false
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 3 | 2 | 1 | 1
4 | 2 | 5 | 4 | 1 | 1
5 | 2 | 4 | 3 | 1 | 2
6 | 2 | 6 | 8 | 1 | 2
7 | 2 | 8 | 7 | 1 | 2
8 | 2 | 10 | 10 | 1 | 2
9 | 2 | 7 | 6 | 1 | 3
10 | 2 | 9 | 16 | 1 | 3
11 | 2 | 11 | 12 | 1 | 3
12 | 2 | 13 | 14 | 1 | 3
13 | 13 | 13 | -1 | 0 | 0
14 | 13 | 10 | 14 | 1 | 1
15 | 13 | 5 | 10 | 1 | 2
16 | 13 | 11 | 12 | 1 | 2
17 | 13 | 2 | 4 | 1 | 3
18 | 13 | 6 | 8 | 1 | 3
19 | 13 | 8 | 7 | 1 | 3
20 | 13 | 12 | 13 | 1 | 3
(20 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,13], 3, false, equicost:=true
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 3 | 2 | 1 | 1
4 | 2 | 5 | 4 | 1 | 1
5 | 2 | 4 | 3 | 1 | 2
6 | 2 | 6 | 8 | 1 | 2
7 | 2 | 8 | 7 | 1 | 2
8 | 2 | 7 | 6 | 1 | 3
9 | 2 | 9 | 16 | 1 | 3
10 | 13 | 13 | -1 | 0 | 0
11 | 13 | 10 | 14 | 1 | 1
12 | 13 | 11 | 12 | 1 | 2
13 | 13 | 12 | 13 | 1 | 3
(13 rows)
Examples for queries marked as directed with cost column¶
The examples in this section use the following Graph 3: Directed, with cost
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
2, 3
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 2 | -1 | 0 | 0
2 | 5 | 4 | 1 | 1
3 | 6 | 8 | 1 | 2
4 | 10 | 10 | 1 | 2
5 | 9 | 9 | 1 | 3
6 | 11 | 11 | 1 | 3
7 | 13 | 14 | 1 | 3
(7 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
13, 3
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 13 | -1 | 0 | 0
(1 row)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
array[2,13], 3
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 5 | 4 | 1 | 1
3 | 2 | 6 | 8 | 1 | 2
4 | 2 | 10 | 10 | 1 | 2
5 | 2 | 9 | 9 | 1 | 3
6 | 2 | 11 | 11 | 1 | 3
7 | 2 | 13 | 14 | 1 | 3
8 | 13 | 13 | -1 | 0 | 0
(8 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
array[2,13], 3, equicost:=true
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 5 | 4 | 1 | 1
3 | 2 | 6 | 8 | 1 | 2
4 | 2 | 10 | 10 | 1 | 2
5 | 2 | 9 | 9 | 1 | 3
6 | 2 | 11 | 11 | 1 | 3
7 | 13 | 13 | -1 | 0 | 0
(7 rows)
Examples for queries marked as undirected with cost column¶
The examples in this section use the following Graph 4: Undirected, with cost
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
2, 3, false
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 2 | -1 | 0 | 0
2 | 1 | 1 | 1 | 1
3 | 5 | 4 | 1 | 1
4 | 6 | 8 | 1 | 2
5 | 8 | 7 | 1 | 2
6 | 10 | 10 | 1 | 2
7 | 3 | 5 | 1 | 3
8 | 7 | 6 | 1 | 3
9 | 9 | 9 | 1 | 3
10 | 11 | 12 | 1 | 3
11 | 13 | 14 | 1 | 3
(11 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
13, 3, false
);
seq | node | edge | cost | agg_cost
-----+------+------+------+----------
1 | 13 | -1 | 0 | 0
2 | 10 | 14 | 1 | 1
3 | 5 | 10 | 1 | 2
4 | 11 | 12 | 1 | 2
5 | 2 | 4 | 1 | 3
6 | 6 | 8 | 1 | 3
7 | 8 | 7 | 1 | 3
8 | 12 | 13 | 1 | 3
(8 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
array[2,13], 3, false
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 5 | 4 | 1 | 1
4 | 2 | 6 | 8 | 1 | 2
5 | 2 | 8 | 7 | 1 | 2
6 | 2 | 10 | 10 | 1 | 2
7 | 2 | 3 | 5 | 1 | 3
8 | 2 | 7 | 6 | 1 | 3
9 | 2 | 9 | 9 | 1 | 3
10 | 2 | 11 | 12 | 1 | 3
11 | 2 | 13 | 14 | 1 | 3
12 | 13 | 13 | -1 | 0 | 0
13 | 13 | 10 | 14 | 1 | 1
14 | 13 | 5 | 10 | 1 | 2
15 | 13 | 11 | 12 | 1 | 2
16 | 13 | 2 | 4 | 1 | 3
17 | 13 | 6 | 8 | 1 | 3
18 | 13 | 8 | 7 | 1 | 3
19 | 13 | 12 | 13 | 1 | 3
(19 rows)
SELECT * FROM pgr_drivingDistance(
'SELECT id, source, target, cost FROM edge_table',
array[2,13], 3, false, equicost:=true
);
seq | from_v | node | edge | cost | agg_cost
-----+--------+------+------+------+----------
1 | 2 | 2 | -1 | 0 | 0
2 | 2 | 1 | 1 | 1 | 1
3 | 2 | 5 | 4 | 1 | 1
4 | 2 | 6 | 8 | 1 | 2
5 | 2 | 8 | 7 | 1 | 2
6 | 2 | 3 | 5 | 1 | 3
7 | 2 | 7 | 6 | 1 | 3
8 | 2 | 9 | 9 | 1 | 3
9 | 13 | 13 | -1 | 0 | 0
10 | 13 | 10 | 14 | 1 | 1
11 | 13 | 11 | 12 | 1 | 2
12 | 13 | 12 | 13 | 1 | 3
(12 rows)
See Also¶
- pgr_alphaShape - Alpha shape computation
- pgr_pointsAsPolygon - Polygon around set of points
- Sample Data network.
Indices and tables