# 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 ANY-INTEGER and ANY-NUMERICAL

• 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

• 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

TEXT

Edges SQL query as described above.

points_sql

TEXT

Points SQL query as described above.

start_vids

ARRAY[ANY-INTEGER]

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

directed

BOOLEAN

(optional). When false the graph is considered as Undirected. Default is true which considers the graph as Directed.

driving_side

CHAR

(optional) Value in [‘b’, ‘r’, ‘l’, NULL] indicating if the driving side is:
• In the right or left or

• If it doesn’t matter with ‘b’ or NULL.

• If column not present ‘b’ is considered.

Returns SET OF (start_vid, end_vid, agg_cost)

Column

Type

Description

start_vid

BIGINT

Identifier of the starting vertex.

end_vid

BIGINT

Identifier of the ending vertex.

agg_cost

FLOAT

Aggregate cost from start_vid to end_vid.

## Inner query¶

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 Points SQL query

points_sql:

an SQL query, which should return a set of rows with the following columns:

Column

Type

Description

pid

ANY-INTEGER

(optional) Identifier of the point.

• If column present, it can not be NULL.

• If column not present, a sequential identifier will be given automatically.

edge_id

ANY-INTEGER

Identifier of the “closest” edge to the point.

fraction

ANY-NUMERICAL

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

side

CHAR

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

• In the right, left of the edge or

• If it doesn’t matter with ‘b’ or NULL.

• If column not present ‘b’ is considered.

Where:

ANY-INTEGER:

smallint, int, bigint

ANY-NUMERICAL:

smallint, int, bigint, real, float

Example:

pgr_TSP using pgr_withPointsCostMatrix for points $$\{1, 6\}$$ and vertices $$\{3, 6\}$$ on an undirected graph

SELECT * FROM pgr_TSP(
$$SELECT * FROM pgr_withPointsCostMatrix( 'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id', 'SELECT pid, edge_id, fraction from pointsOfInterest', array[-1, 3, 6, -6], directed := false);$$
);
seq | node | cost | agg_cost
-----+------+------+----------
1 |   -6 |    0 |        0
2 |   -1 |  1.3 |      1.3
3 |    3 |  1.6 |      2.9
4 |    6 |    1 |      3.9
5 |   -6 |  1.3 |      5.2
(5 rows)