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 the Dijkstra algorithm, extracts all the nodes that have costs less than or equal to the value distance. The edges extracted will conform to 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) When negative: edge (source, target) does not exist, therefore it’s not part of the graph.
reverse_cost	`ANY-NUMERICAL`	-1	Weight of the edge (target, source), When negative: edge (target, source) does not exist, therefore it’s not part of the graph.

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 the 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 arbitrary.

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 Network for queries marked as directed and cost and reverse_cost columns are used

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 Network for queries marked as undirected and cost and reverse_cost columns are used

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 Network for queries marked as directed and only cost column is used

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 Network for queries marked as undirected and only cost column is used

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)