Hi,
I use pgRouting to calculate accessible routes for disabled pedestrians.
Network edges have some attributes that are used to filter the accessible network in both ways depending on the user capacities (where clause).
Network edges have also attributes that are used to update cost / rev_cost depending on the routing way : If an edge is forbidden in the digitizing way, cost is set to 1 000 000. If it is forbidden in the reverse way, rev_cost is set to 1 000 000. If it is forbidden in both ways, cost and rev_cost are set to 1 000 000.
Now, in some cases, despite there is no accessible route according to the where clause, pgr_trsp() returns a route going through edges with cost / rev_cost set to 1 000 000.
If I change the where clause so that there is actually an alternative route, same edges with cost / rev_cost set to 1 000 000 are taken into account, and the calculated route is correct.
I attached to this message images of both results (forbidden edges in red, returned paths in blue).
Routing is calculated from edge n°18295 (vertex n°19314) to edge n°23805 (vertex n°10776).
Wrong edge is n°30606 in test 2.
Here is the sql code of the first test :
SELECT * FROM pgr_trsp(
'SELECT id_tron::integer AS id, source::integer, target::integer,
cost::double precision, rev_cost::double precision AS reverse_cost
FROM rp_test
WHERE type_tron NOT IN(3, 8, 9) AND largeur_c > 90 AND largeur_p > 75 AND etat_revet >= 2',
19314::INTEGER, 10776::INTEGER, true, true,
'SELECT to_cost::double precision, target_id::integer, via_path::text FROM reseau_global_rest');
And here is the sql code of the second test :
SELECT * FROM pgr_trsp(
'SELECT id_tron::integer AS id, source::integer, target::integer,
cost::double precision, rev_cost::double precision AS reverse_cost
FROM rp_test
WHERE type_tron NOT IN(3, 8, 9) AND largeur_c > 90 AND largeur_p > 75',
19314::INTEGER, 10776::INTEGER, true, true,
'SELECT to_cost::double precision, target_id::integer, via_path::text FROM reseau_global_rest');
I also attach to this message a shape file of the network.
Do I miss something, or is it a bug ?
Thanks for any help,
--
Christophe DAMOUR