pgr_withPoints  Proposed¶
pgr_withPoints
 Returns the shortest path in a graph with additional temporary vertices.
Warning
Proposed functions for next mayor release.
They are not officially in the current release.
They will likely officially be part of the next mayor release:
The functions make use of ANYINTEGER and ANYNUMERICAL
Name might not change. (But still can)
Signature might not change. (But still can)
Functionality might not change. (But still can)
pgTap tests have being done. But might need more.
Documentation might need refinement.
Availability
Version 2.2.0
New proposed function
Support
Description¶
Modify the graph to include points defined by points_sql. Using Dijkstra algorithm, find the shortest path(s)
The main characteristics are:
Process is done only on edges with positive costs.
Vertices of the graph are:
positive when it belongs to the edges_sql
negative when it belongs to the points_sql
Values are returned when there is a path.
When the starting vertex and ending vertex are the same, there is no path.  The agg_cost the non included values (v, v) is 0
When the starting vertex and ending vertex are the different and there is no path:  The agg_cost the non included values (u, v) is ∞
For optimization purposes, any duplicated value in the start_vids or end_vids are ignored.
The returned values are ordered:  start_vid ascending  end_vid ascending
Running time: \(O(start\_vids\times(V \log V + E))\)
Signatures¶
Summary
pgr_withPoints(edges_sql, points_sql, from_vid, to_vid [, directed] [, driving_side] [, details])
pgr_withPoints(edges_sql, points_sql, from_vid, to_vids [, directed] [, driving_side] [, details])
pgr_withPoints(edges_sql, points_sql, from_vids, to_vid [, directed] [, driving_side] [, details])
pgr_withPoints(edges_sql, points_sql, from_vids, to_vids [, directed] [, driving_side] [, details])
RETURNS SET OF (seq, path_seq, [start_vid,] [end_vid,] node, edge, cost, agg_cost)
Using defaults
pgr_withPoints(edges_sql, points_sql, from_vid, to_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
 Example
From point \(1\) to point \(3\)
For a directed graph.
The driving side is set as b both. So arriving/departing to/from the point(s) can be in any direction.
No details are given about distance of other points of points_sql query.
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
1, 3);
seq  path_seq  node  edge  cost  agg_cost
+++++
1  1  1  1  0.6  0
2  2  2  4  1  0.6
3  3  5  10  1  1.6
4  4  10  12  0.6  2.6
5  5  3  1  0  3.2
(5 rows)
One to One¶
pgr_withPoints(edges_sql, points_sql, from_vid, to_vid [, directed] [, driving_side] [, details])
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
 Example
From point \(1\) to vertex \(3\) with details of passing points
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
1, 3,
details := true);
seq  path_seq  node  edge  cost  agg_cost
+++++
1  1  1  1  0.6  0
2  2  2  4  0.7  0.6
3  3  6  4  0.3  1.3
4  4  5  8  1  1.6
5  5  6  9  1  2.6
6  6  9  16  1  3.6
7  7  4  3  1  4.6
8  8  3  1  0  5.6
(8 rows)
One to Many¶
pgr_withPoints(edges_sql, points_sql, from_vid, to_vids [, directed] [, driving_side] [, details])
RETURNS SET OF (seq, path_seq, end_vid, node, edge, cost, agg_cost)
 Example
From point \(1\) to point \(3\) and vertex \(5\)
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
1, ARRAY[3,5]);
seq  path_seq  end_pid  node  edge  cost  agg_cost
++++++
1  1  3  1  1  0.6  0
2  2  3  2  4  1  0.6
3  3  3  5  10  1  1.6
4  4  3  10  12  0.6  2.6
5  5  3  3  1  0  3.2
6  1  5  1  1  0.6  0
7  2  5  2  4  1  0.6
8  3  5  5  1  0  1.6
(8 rows)
Many to One¶
pgr_withPoints(edges_sql, points_sql, from_vids, to_vid [, directed] [, driving_side] [, details])
RETURNS SET OF (seq, path_seq, start_vid, node, edge, cost, agg_cost)
 Example
From point \(1\) and vertex \(2\) to point \(3\)
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
ARRAY[1,2], 3);
seq  path_seq  start_pid  node  edge  cost  agg_cost
++++++
1  1  1  1  1  0.6  0
2  2  1  2  4  1  0.6
3  3  1  5  10  1  1.6
4  4  1  10  12  0.6  2.6
5  5  1  3  1  0  3.2
6  1  2  2  4  1  0
7  2  2  5  10  1  1
8  3  2  10  12  0.6  2
9  4  2  3  1  0  2.6
(9 rows)
Many to Many¶
pgr_withPoints(edges_sql, points_sql, from_vids, to_vids [, directed] [, driving_side] [, details])
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
 Example
From point \(1\) and vertex \(2\) to point \(3\) and vertex \(7\)
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
ARRAY[1,2], ARRAY[3,7]);
seq  path_seq  start_pid  end_pid  node  edge  cost  agg_cost
+++++++
1  1  1  3  1  1  0.6  0
2  2  1  3  2  4  1  0.6
3  3  1  3  5  10  1  1.6
4  4  1  3  10  12  0.6  2.6
5  5  1  3  3  1  0  3.2
6  1  1  7  1  1  0.6  0
7  2  1  7  2  4  1  0.6
8  3  1  7  5  7  1  1.6
9  4  1  7  8  6  1  2.6
10  5  1  7  7  1  0  3.6
11  1  2  3  2  4  1  0
12  2  2  3  5  10  1  1
13  3  2  3  10  12  0.6  2
14  4  2  3  3  1  0  2.6
15  1  2  7  2  4  1  0
16  2  2  7  5  7  1  1
17  3  2  7  8  6  1  2
18  4  2  7  7  1  0  3
(18 rows)
Parameters¶
Parameter 
Type 
Description 

edges_sql 

Edges SQL query as described above. 
points_sql 

Points SQL query as described above. 
start_vid 

Starting vertex identifier. When negative: is a point’s pid. 
end_vid 

Ending vertex identifier. When negative: is a point’s pid. 
start_vids 

Array of identifiers of starting vertices. When negative: is a point’s pid. 
end_vids 

Array of identifiers of ending vertices. When negative: is a point’s pid. 
directed 

(optional). When 
driving_side 


details 

(optional). When 
Inner 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:
 ANYINTEGER
SMALLINT, INTEGER, BIGINT
 ANYNUMERICAL
SMALLINT, INTEGER, BIGINT, REAL, FLOAT
Description of the Points SQL query
 points_sql
an SQL query, which should return a set of rows with the following columns:
Column 
Type 
Description 

pid 

(optional) Identifier of the point.

edge_id 

Identifier of the “closest” edge to the point. 
fraction 

Value in <0,1> that indicates the relative postition from the first end point of the edge. 
side 

(optional) Value in [‘b’, ‘r’, ‘l’, NULL] indicating if the point is:

Where:
 ANYINTEGER
smallint, int, bigint
 ANYNUMERICAL
smallint, int, bigint, real, float
Result Columns¶
Column 
Type 
Description 

seq 

Row sequence. 
path_seq 

Path sequence that indicates the relative position on the path. 
start_vid 

Identifier of the starting vertex. When negative: is a point’s pid. 
end_vid 

Identifier of the ending vertex. When negative: is a point’s pid. 
node 


edge 


cost 


agg_cost 


Additional Examples¶
 Example
Which path (if any) passes in front of point \(6\) or vertex \(6\) with right side driving topology.
SELECT ('('  start_pid  ' => '  end_pid ') at '  path_seq  'th step:')::TEXT AS path_at,
CASE WHEN edge = 1 THEN ' visits'
ELSE ' passes in front of'
END as status,
CASE WHEN node < 0 THEN 'Point'
ELSE 'Vertex'
END as is_a,
abs(node) as id
FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
ARRAY[1,1], ARRAY[2,3,6,3,6],
driving_side := 'r',
details := true)
WHERE node IN (6,6);
path_at  status  is_a  id
+++
(1 => 6) at 4th step:  visits  Point  6
(1 => 3) at 4th step:  passes in front of  Point  6
(1 => 2) at 4th step:  passes in front of  Point  6
(1 => 2) at 6th step:  passes in front of  Vertex  6
(1 => 3) at 4th step:  passes in front of  Point  6
(1 => 3) at 6th step:  passes in front of  Vertex  6
(1 => 6) at 4th step:  passes in front of  Point  6
(1 => 6) at 6th step:  visits  Vertex  6
(1 => 6) at 3th step:  visits  Point  6
(1 => 3) at 3th step:  passes in front of  Point  6
(1 => 2) at 3th step:  passes in front of  Point  6
(1 => 2) at 5th step:  passes in front of  Vertex  6
(1 => 3) at 3th step:  passes in front of  Point  6
(1 => 3) at 5th step:  passes in front of  Vertex  6
(1 => 6) at 3th step:  passes in front of  Point  6
(1 => 6) at 5th step:  visits  Vertex  6
(16 rows)
 Example
Which path (if any) passes in front of point \(6\) or vertex \(6\) with left side driving topology.
SELECT ('('  start_pid  ' => '  end_pid ') at '  path_seq  'th step:')::TEXT AS path_at,
CASE WHEN edge = 1 THEN ' visits'
ELSE ' passes in front of'
END as status,
CASE WHEN node < 0 THEN 'Point'
ELSE 'Vertex'
END as is_a,
abs(node) as id
FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
ARRAY[1,1], ARRAY[2,3,6,3,6],
driving_side := 'l',
details := true)
WHERE node IN (6,6);
path_at  status  is_a  id
+++
(1 => 6) at 3th step:  visits  Point  6
(1 => 3) at 3th step:  passes in front of  Point  6
(1 => 2) at 3th step:  passes in front of  Point  6
(1 => 2) at 5th step:  passes in front of  Vertex  6
(1 => 3) at 3th step:  passes in front of  Point  6
(1 => 3) at 5th step:  passes in front of  Vertex  6
(1 => 6) at 3th step:  passes in front of  Point  6
(1 => 6) at 5th step:  visits  Vertex  6
(1 => 6) at 4th step:  visits  Point  6
(1 => 3) at 4th step:  passes in front of  Point  6
(1 => 2) at 4th step:  passes in front of  Point  6
(1 => 2) at 6th step:  passes in front of  Vertex  6
(1 => 3) at 4th step:  passes in front of  Point  6
(1 => 3) at 6th step:  passes in front of  Vertex  6
(1 => 6) at 4th step:  passes in front of  Point  6
(1 => 6) at 6th step:  visits  Vertex  6
(16 rows)
 Example
From point \(1\) and vertex \(2\) to point \(3\) to vertex \(7\) on an undirected graph, with details.
SELECT * FROM pgr_withPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction, side from pointsOfInterest',
ARRAY[1,2], ARRAY[3,7],
directed := false,
details := true);
seq  path_seq  start_pid  end_pid  node  edge  cost  agg_cost
+++++++
1  1  1  3  1  1  0.6  0
2  2  1  3  2  4  0.7  0.6
3  3  1  3  6  4  0.3  1.3
4  4  1  3  5  10  1  1.6
5  5  1  3  10  12  0.6  2.6
6  6  1  3  3  1  0  3.2
7  1  1  7  1  1  0.6  0
8  2  1  7  2  4  0.7  0.6
9  3  1  7  6  4  0.3  1.3
10  4  1  7  5  7  1  1.6
11  5  1  7  8  6  0.7  2.6
12  6  1  7  4  6  0.3  3.3
13  7  1  7  7  1  0  3.6
14  1  2  3  2  4  0.7  0
15  2  2  3  6  4  0.3  0.7
16  3  2  3  5  10  1  1
17  4  2  3  10  12  0.6  2
18  5  2  3  3  1  0  2.6
19  1  2  7  2  4  0.7  0
20  2  2  7  6  4  0.3  0.7
21  3  2  7  5  7  1  1
22  4  2  7  8  6  0.7  2
23  5  2  7  4  6  0.3  2.7
24  6  2  7  7  1  0  3
(24 rows)
The queries use the Sample Data network