pgr_bdAstarCostMatrix
 Calculates the a cost matrix using pgr_bdAstar.
Availability: 2.5.0
Warning
Experimental functions
Using Dijkstra algorithm, calculate and return a cost matrix.
pgr_bdAstarCostMatrix(edges_sql, start_vids)
pgr_bdAstarCostMatrix(edges_sql, start_vids, [, directed , heuristic, factor, epsilon])
RETURNS SET OF (start_vid, end_vid, agg_cost)
OR EMPTY SET
pgr_bdAstarCostMatrix(edges_sql, start_vids)
RETURNS SET OF (start_vid, end_vid, agg_cost)
OR EMPTY SET
start_vid
in start_vids
to each start_vid
in start_vids
Example:  Cost matrix for vertices 1, 2, 3, and 4. 

SELECT * FROM pgr_bdAstarCostMatrix(
'SELECT id, source, target, cost, reverse_cost, x1, y1, x2, y2 FROM edge_table',
(SELECT array_agg(id) FROM edge_table_vertices_pgr WHERE id < 5)
);
start_vid  end_vid  agg_cost
++
1  2  1
1  3  6
1  4  5
2  1  1
2  3  5
2  4  4
3  1  2
3  2  1
3  4  3
4  1  3
4  2  2
4  3  1
(12 rows)
pgr_bdAstarCostMatrix(edges_sql, start_vids, [, directed , heuristic, factor, epsilon])
RETURNS SET OF (start_vid, end_vid, agg_cost)
OR EMPTY SET
start_vid
in start_vids
to each start_vid
in start_vids
allowing the user to chooseExample:  Cost matrix for an undirected graph for vertices 1, 2, 3, and 4. 

This example returns a symmetric cost matrix.
SELECT * FROM pgr_bdAstarCostMatrix(
'SELECT id, source, target, cost, reverse_cost, x1, y1, x2, y2 FROM edge_table',
(SELECT array_agg(id) FROM edge_table_vertices_pgr WHERE id < 5),
false
);
start_vid  end_vid  agg_cost
++
1  2  1
1  3  2
1  4  3
2  1  1
2  3  1
2  4  2
3  1  2
3  2  1
3  4  1
4  1  3
4  2  2
4  3  1
(12 rows)
edges_sql:  an SQL query, which should return a set of rows with the following columns: 

Column  Type  Default  Description 

id  ANYINTEGER 
Identifier of the edge.  
source  ANYINTEGER 
Identifier of the first end point vertex of the edge.  
target  ANYINTEGER 
Identifier of the second end point vertex of the edge.  
cost  ANYNUMERICAL 
Weight of the edge (source, target)


reverse_cost  ANYNUMERICAL 
1  Weight of the edge (target, source),

x1  ANYNUMERICAL 
X coordinate of source vertex.  
y1  ANYNUMERICAL 
Y coordinate of source vertex.  
x2  ANYNUMERICAL 
X coordinate of target vertex.  
y2  ANYNUMERICAL 
Y coordinate of target vertex. 
Where:
ANYINTEGER:  SMALLINT, INTEGER, BIGINT 

ANYNUMERICAL:  SMALLINT, INTEGER, BIGINT, REAL, FLOAT 
Parameter  Type  Description 

edges_sql  TEXT 
Edges SQL query as described above. 
start_vid  ANYINTEGER 
Starting vertex identifier. 
start_vids  ARRAY[ANYINTEGER] 
Starting vertices identifierers. 
end_vid  ANYINTEGER 
Ending vertex identifier. 
end_vids  ARRAY[ANYINTEGER] 
Ending vertices identifiers. 
directed  BOOLEAN 

heuristic  INTEGER 
(optional). Heuristic number. Current valid values 0~5. Default

factor  FLOAT 
(optional). For units manipulation. \(factor > 0\). Default 1 . see Factor 
epsilon  FLOAT 
(optional). For less restricted results. \(epsilon >= 1\). Default 1 . 
Returns set of (start_vid, end_vid, agg_cost)
Column  Type  Description 

start_vid  BIGINT 
Identifier of the starting vertex. Used when multiple starting vetrices are in the query. 
end_vid  BIGINT 
Identifier of the ending vertex. Used when multiple ending vertices are in the query. 
agg_cost  FLOAT 
Aggregate cost from start_vid to end_vid . 
Example:  Use with tsp 

SELECT * FROM pgr_TSP(
$$
SELECT * FROM pgr_bdAstarCostMatrix(
'SELECT id, source, target, cost, reverse_cost, x1, y1, x2, y2 FROM edge_table',
(SELECT array_agg(id) FROM edge_table_vertices_pgr WHERE id < 5),
false
)
$$,
randomize := false
);
seq  node  cost  agg_cost
+++
1  1  1  0
2  2  1  1
3  3  1  2
4  4  3  3
5  1  0  6
(5 rows)
Indices and tables