pgr_withPointsCostMatrix  proposed¶
pgr_withPointsCostMatrix
 Calculates the shortest path and returns only the aggregate cost of the shortest path(s) found, for the combination of points given.
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
Description¶
TBD
Signatures¶
Summary
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vids [, directed] [, driving_side])
RETURNS SET OF (start_vid, end_vid, agg_cost)
Note
There is no details flag, unlike the other members of the withPoints family of functions.
Using default
 The minimal signature:
Is 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.
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vid)
RETURNS SET OF (start_vid, end_vid, agg_cost)
 Example
Cost matrix for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on a directed graph
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[1, 3, 6, 6]);
start_vid  end_vid  agg_cost
++
6  1  1.3
6  3  4.3
6  6  1.3
1  6  1.3
1  3  5.6
1  6  2.6
3  6  1.7
3  1  1.6
3  6  1
6  6  1.3
6  1  2.6
6  3  3
(12 rows)
Complete Signature¶
pgr_withPointsCostMatrix(edges_sql, points_sql, start_vids,
directed:=true, driving_side:='b')
RETURNS SET OF (start_vid, end_vid, agg_cost)
 Example
Cost matrix for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on an undirected graph
Returning a symmetrical cost matrix
Using the default side value on the points_sql query
Using the default driving_side value
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[1, 3, 6, 6], directed := false);
start_vid  end_vid  agg_cost
++
6  1  1.3
6  3  1.7
6  6  1.3
1  6  1.3
1  3  1.6
1  6  2.6
3  6  1.7
3  1  1.6
3  6  1
6  6  1.3
6  1  2.6
6  3  1
(12 rows)
Parameters¶
Parameter 
Type 
Description 

edges_sql 

Edges SQL query as described above. 
points_sql 

Points SQL query as described above. 
start_vids 

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

(optional). When 
driving_side 


Returns SET OF (start_vid, end_vid, agg_cost)
Column 
Type 
Description 

start_vid 

Identifier of the starting vertex. 
end_vid 

Identifier of the ending vertex. 
agg_cost 

Aggregate cost from 
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
Additional Examples¶
 Example
pgr_TSP using
pgr_withPointsCostMatrix
for points \(\{1, 6\}\) and vertices \(\{3, 6\}\) on an undirected graph
SELECT * FROM pgr_TSP(
$$
SELECT * FROM pgr_withPointsCostMatrix(
'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
'SELECT pid, edge_id, fraction from pointsOfInterest',
array[1, 3, 6, 6], directed := false);
$$,
randomize := false
);
seq  node  cost  agg_cost
+++
1  6  1.3  0
2  1  1.6  1.3
3  3  1  2.9
4  6  1.3  3.9
5  6  0  5.2
(5 rows)