pgr_lineGraph
 Experimental¶
pgr_lineGraph
— Transforms the given graph into its corresponding edgebased
graph.
Warning
Possible server crash
These functions might create a server crash
Warning
Experimental functions
They are not officially of the current release.
They likely will not be officially be part of the next release:
The functions might not make use of ANYINTEGER and ANYNUMERICAL
Name might change.
Signature might change.
Functionality might change.
pgTap tests might be missing.
Might need c/c++ coding.
May lack documentation.
Documentation if any might need to be rewritten.
Documentation examples might need to be automatically generated.
Might need a lot of feedback from the comunity.
Might depend on a proposed function of pgRouting
Might depend on a deprecated function of pgRouting
Availability
Version 2.5.0
New Experimental function
Description¶
Given a graph G, its line graph L(G) is a graph such that:
Each vertex of L(G) represents an edge of G
Two vertices of L(G) are adjacent if and only if their corresponding edges share a common endpoint in G.
Signatures¶
directed
])(seq, source, target, cost, reverse_cost)
 Example:
For a directed graph
SELECT * FROM pgr_lineGraph(
'SELECT id, source, target, cost, reverse_cost FROM edges'
);
seq  source  target  cost  reverse_cost
++++
1  18  18  1  1
2  17  17  1  1
3  16  3  1  1
4  14  10  1  1
5  14  12  1  1
6  14  14  1  1
7  10  7  1  1
8  10  4  1  1
9  10  8  1  1
10  10  10  1  1
11  9  8  1  1
12  9  9  1  1
13  9  11  1  1
14  8  7  1  1
15  8  4  1  1
16  8  8  1  1
17  7  6  1  1
18  7  7  1  1
19  6  6  1  1
20  3  2  1  1
21  3  5  1  1
22  2  1  1  1
23  2  4  1  1
24  1  1  1  1
25  1  4  1  1
26  4  7  1  1
27  4  4  1  1
28  5  8  1  1
29  5  9  1  1
30  5  11  1  1
31  8  11  1  1
32  9  16  1  1
33  9  15  1  1
34  10  12  1  1
35  11  13  1  1
36  12  13  1  1
37  13  15  1  1
38  15  15  1  1
39  16  16  1  1
40  16  15  1  1
(40 rows)
Parameters¶
Parameter 
Type 
Description 


Edges SQL as described below. 
Optional parameters¶
Column 
Type 
Default 
Description 





Inner Queries¶
Edges SQL¶
Column 
Type 
Default 
Description 


ANYINTEGER 
Identifier of the edge. 


ANYINTEGER 
Identifier of the first end point vertex of the edge. 


ANYINTEGER 
Identifier of the second end point vertex of the edge. 


ANYNUMERICAL 
Weight of the edge ( 


ANYNUMERICAL 
1 
Weight of the edge (

Where:
 ANYINTEGER:
SMALLINT
,INTEGER
,BIGINT
 ANYNUMERICAL:
SMALLINT
,INTEGER
,BIGINT
,REAL
,FLOAT
Result Columns¶
RETURNS SET OF (seq, source, target, cost, reverse_cost)
Column 
Type 
Description 



Sequential value starting from 1.



Identifier of the source vertex of the current edge.



Identifier of the target vertex of the current edge.



Weight of the edge (



Weight of the edge (

See Also¶
The queries use the Sample Data network.
Indices and tables