Is there any interest in any off the above graph forms in the routing library?
See
https://en.wikipedia.org/wiki/Beta_skeleton
https://en.wikipedia.org/wiki/Relative_neighborhood_graph
https://en.wikipedia.org/wiki/Gabriel_graph
I have implementation with the following method signatures
CREATE OR REPLACE FUNCTION pgr_beta_skelton(sql text, beta float,OUT id integer ,OUT id1 integer , OUT id2 integer)
RETURNS SETOF RECORD AS
‘$libdir/librouting-2.1’, ‘dir_graph_beta_skelton’
LANGUAGE c STABLE STRICT;
CREATE OR REPLACE FUNCTION pgr_relative_neigborhood_graph(sql text ,OUT id integer ,OUT id1 integer , OUT id2 integer)
RETURNS SETOF RECORD AS
‘$libdir/librouting-2.1’, ‘dir_graph_relative_neigborhood_graph’
LANGUAGE c STABLE STRICT;
CREATE OR REPLACE FUNCTION pgr_gabriel_graph(sql text ,OUT id integer ,OUT id1 integer , OUT id2 integer)
RETURNS SETOF RECORD AS
‘$libdir/librouting-2.1’, ‘dir_graph_gabriel_graph’
LANGUAGE c STABLE STRICT;
They all take an sql statement of the form
select st_makeline(v1.the_geom,v2.the_geom) as the_geom from pgr_gabriel_graph(‘select id,st_x(the_geom) as x ,st_y(the_geom) as y from tmp_table2’), tmp_table2 v1, tmp_table2 v2 where id1=v1.id and id2=v2.id;
Ie the expect an set of objects with an id and a x and y coordinate
In this example tmp_table functions as resource of data, and the above statement returns a serries of id statements id refers to id of 1st x/y node and the 2nd id refers to 2md x/y pair
eg
id | id1 | id2
-----±----±----
1 | 607 | 558
2 | 606 | 542
3 | 605 | 594
4 | 605 | 520
5 | 604 | 579
6 | 604 | 525
7 | 603 | 605
8 | 603 | 594
9 | 603 | 530
10 | 602 | 580
11 | 602 | 563
12 | 601 | 537
13 | 601 | 534
14 | 600 | 523
15 | 599 | 601
16 | 599 | 522
17 | 598 | 590
regards
Dave.