pgr_trspVia - Proposed¶
pgr_trspVia Route that goes through a list of vertices with restrictions.
Adentro: Boost Graph¶
Advertencia
Funciones propuestas para la próxima versión mayor.
No están oficialmente en la versión actual.
Es probable que oficialmente formen parte del próximo lanzamiento:
Las funciones hacen uso de ENTEROS y FLOTANTES
Probablemente el nombre no cambie. (Pero todavía puede)
Es posible que la firma no cambie. (Pero todavía puede)
Probablemente la funcionalidad no cambie. (Pero todavía puede)
Se han hecho pruebas con pgTap. Pero tal vez se necesiten más.
Es posible que la documentación necesite un refinamiento.
Disponibilidad
Versión 3.4.0
New proposed function:
pgr_trspVia(One Via)
Descripción¶
Given a list of vertices and a graph, this function is equivalent to finding the shortest path between \(vertex_i\) and \(vertex_{i+1}\) for all \(i < size\_of(via\;vertices)\) trying not to use restricted paths.
Las trayectorias representan los tramos de la ruta.
The general algorithm is as follows:
Execute a pgr_dijkstraVia - Propuesto.
For the set of sub paths of the solution that pass through a restriction then
Execute the TRSP algorithm with restrictions for the paths.
NOTE when this is done,
U_turn_on_edgeflag is ignored.
Firmas¶
Una Vía¶
[directed, strict, U_turn_on_edge](seq, path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost, route_agg_cost)- Ejemplo:
Encontrar la ruta que visita los vértices \({5, 1, 8\}\) en ese orden en un grafo dirigido.
SELECT * FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 1, 8]);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 5 | 1 | 5 | 1 | 1 | 0 | 0
2 | 1 | 2 | 5 | 1 | 6 | 4 | 1 | 1 | 1
3 | 1 | 3 | 5 | 1 | 7 | 10 | 1 | 2 | 2
4 | 1 | 4 | 5 | 1 | 8 | 12 | 1 | 3 | 3
5 | 1 | 5 | 5 | 1 | 12 | 13 | 1 | 4 | 4
6 | 1 | 6 | 5 | 1 | 17 | 15 | 1 | 5 | 5
7 | 1 | 7 | 5 | 1 | 16 | 9 | 1 | 6 | 6
8 | 1 | 8 | 5 | 1 | 11 | 8 | 1 | 7 | 7
9 | 1 | 9 | 5 | 1 | 7 | 7 | 1 | 8 | 8
10 | 1 | 10 | 5 | 1 | 3 | 6 | 1 | 9 | 9
11 | 1 | 11 | 5 | 1 | 1 | -1 | 0 | 10 | 10
12 | 2 | 1 | 1 | 8 | 1 | 6 | 1 | 0 | 10
13 | 2 | 2 | 1 | 8 | 3 | 7 | 1 | 1 | 11
14 | 2 | 3 | 1 | 8 | 7 | 10 | 101 | 2 | 12
15 | 2 | 4 | 1 | 8 | 8 | -2 | 0 | 103 | 113
(15 rows)
Parámetros¶
Parámetro |
Tipo |
Descripción |
|---|---|---|
|
SQL de aristas como se describen. |
|
|
SQL de restricciones consulta como se describe. |
|
vértices |
|
Arreglo ordenado de identificadores de vértices que serán visitados. |
Donde:
- ENTEROS:
SMALLINT, INTEGER, BIGINT
Parámetros opcionales¶
Columna |
Tipo |
x Defecto |
Descripción |
|---|---|---|---|
|
|
|
|
Parámetros opcionales Vía¶
Parámetro |
Tipo |
x Defecto |
Descripción |
|---|---|---|---|
|
|
|
|
|
|
|
|
Consultas Internas¶
SQL aristas¶
Columna |
Tipo |
x Defecto |
Descripción |
|---|---|---|---|
|
ENTEROS |
Identificador de la arista. |
|
|
ENTEROS |
Identificador del primer vértice de la arista. |
|
|
ENTEROS |
Identificador del segundo vértice de la arista. |
|
|
FLOTANTES |
Peso de la arista ( |
|
|
FLOTANTES |
-1 |
Peso de la arista (
|
Donde:
- ENTEROS:
SMALLINT,INTEGER,BIGINT- FLOTANTES:
SMALLINT,INTEGER,BIGINT,REAL,FLOAT
SQL restricciones¶
Columna |
Tipo |
Descripción |
|---|---|---|
|
|
Secuencia de identificadores de aristas que forman un camino que no se permite tomar. - Arreglos vacios o |
|
FLOTANTES |
Costo de tomar el camino prohibido. |
Donde:
- ENTEROS:
SMALLINT,INTEGER,BIGINT- FLOTANTES:
SMALLINT,INTEGER,BIGINT,REAL,FLOAT
Columnas de resultados¶
Columna |
Tipo |
Descripción |
|---|---|---|
|
|
Valor secuencial a partir de 1. |
|
|
Identificador del camino. Tiene valor 1 para el primer camino. |
|
|
Posición relativa en la ruta. Tiene el valor 1 para el inicio de una ruta. |
|
|
Identificador del vértice inicial de la ruta. |
|
|
Identificador del vértice final de la ruta. |
|
|
Identificador del nodo en la ruta de |
|
|
Identificador de la arsita utilizada para ir del
|
|
|
Costo para atravesar desde |
|
|
Costo agregado desde |
|
|
Costo total desde |
Ejemplos Adicionales¶
Todos estos ejemplos son sobre la ruta que visita los vértices \(\{5, 7, 1, 8, 15\}\) en ese orden, en un grafo dirigido.
La consulta principal¶
SELECT * FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15]);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 5 | 7 | 5 | 1 | 1 | 0 | 0
2 | 1 | 2 | 5 | 7 | 6 | 4 | 1 | 1 | 1
3 | 1 | 3 | 5 | 7 | 7 | -1 | 0 | 2 | 2
4 | 2 | 1 | 7 | 1 | 7 | 7 | 1 | 0 | 2
5 | 2 | 2 | 7 | 1 | 3 | 6 | 1 | 1 | 3
6 | 2 | 3 | 7 | 1 | 1 | -1 | 0 | 2 | 4
7 | 3 | 1 | 1 | 8 | 1 | 6 | 1 | 0 | 4
8 | 3 | 2 | 1 | 8 | 3 | 7 | 1 | 1 | 5
9 | 3 | 3 | 1 | 8 | 7 | 10 | 101 | 2 | 6
10 | 3 | 4 | 1 | 8 | 8 | -1 | 0 | 103 | 107
11 | 4 | 1 | 8 | 15 | 8 | 12 | 1 | 0 | 107
12 | 4 | 2 | 8 | 15 | 12 | 13 | 1 | 1 | 108
13 | 4 | 3 | 8 | 15 | 17 | 15 | 1 | 2 | 109
14 | 4 | 4 | 8 | 15 | 16 | 16 | 1 | 3 | 110
15 | 4 | 5 | 8 | 15 | 15 | -2 | 0 | 4 | 111
(15 rows)
Costo agregado de la tercera ruta.¶
SELECT agg_cost FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge < 0;
agg_cost
----------
103
(1 row)
Costo agregado al final de la tercera ruta.¶
SELECT route_agg_cost FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge < 0;
route_agg_cost
----------------
107
(1 row)
Nodos visitados en la ruta.¶
SELECT row_number() over () as node_seq, node
FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15])
WHERE edge <> -1 ORDER BY seq;
node_seq | node
----------+------
1 | 5
2 | 6
3 | 7
4 | 3
5 | 1
6 | 3
7 | 7
8 | 8
9 | 12
10 | 17
11 | 16
12 | 15
(12 rows)
Costo agregado de la ruta al llegar a los vértices visitados.¶
SELECT path_id, route_agg_cost FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15])
WHERE edge < 0;
path_id | route_agg_cost
---------+----------------
1 | 2
2 | 4
3 | 107
4 | 111
(4 rows)
Estado de «pasa enfrente» o «visita» los nodos.¶
SELECT seq, route_agg_cost, node, agg_cost ,
CASE WHEN edge = -1 THEN $$visits$$
ELSE $$passes in front$$
END as status
FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[5, 7, 1, 8, 15])
WHERE agg_cost <> 0 or seq = 1;
seq | route_agg_cost | node | agg_cost | status
-----+----------------+------+----------+-----------------
1 | 0 | 5 | 0 | passes in front
2 | 1 | 6 | 1 | passes in front
3 | 2 | 7 | 2 | visits
5 | 3 | 3 | 1 | passes in front
6 | 4 | 1 | 2 | visits
8 | 5 | 3 | 1 | passes in front
9 | 6 | 7 | 2 | passes in front
10 | 107 | 8 | 103 | visits
12 | 108 | 12 | 1 | passes in front
13 | 109 | 17 | 2 | passes in front
14 | 110 | 16 | 3 | passes in front
15 | 111 | 15 | 4 | passes in front
(12 rows)
Sumulación del functionamiento del algoritmo.¶
The algorithm performs a pgr_dijkstraVia - Propuesto
SELECT * FROM pgr_dijkstraVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
ARRAY[6, 3, 6]);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 6 | 3 | 6 | 4 | 1 | 0 | 0
2 | 1 | 2 | 6 | 3 | 7 | 7 | 1 | 1 | 1
3 | 1 | 3 | 6 | 3 | 3 | -1 | 0 | 2 | 2
4 | 2 | 1 | 3 | 6 | 3 | 7 | 1 | 0 | 2
5 | 2 | 2 | 3 | 6 | 7 | 4 | 1 | 1 | 3
6 | 2 | 3 | 3 | 6 | 6 | -2 | 0 | 2 | 4
(6 rows)
Detects which of the sub paths pass through a restriction in this case is for
the path_id = 5 from 6 to 3 because the path \(15 \rightarrow 1\)
is restricted.
Executes the pgr_trsp - Proposed algorithm for the conflicting paths.
SELECT 1 AS path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost FROM pgr_trsp(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
6, 3);
path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
---------+----------+-----------+---------+------+------+------+----------
1 | 1 | 6 | 3 | 6 | 4 | 1 | 0
1 | 2 | 6 | 3 | 7 | 10 | 1 | 1
1 | 3 | 6 | 3 | 8 | 12 | 1 | 2
1 | 4 | 6 | 3 | 12 | 13 | 1 | 3
1 | 5 | 6 | 3 | 17 | 15 | 1 | 4
1 | 6 | 6 | 3 | 16 | 9 | 1 | 5
1 | 7 | 6 | 3 | 11 | 8 | 1 | 6
1 | 8 | 6 | 3 | 7 | 7 | 1 | 7
1 | 9 | 6 | 3 | 3 | -1 | 0 | 8
(9 rows)
From the pgr_dijkstraVia - Propuesto result it removes the conflicting paths and builds the solution with the results of the pgr_trsp - Proposed algorithm:
WITH
solutions AS (
SELECT path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost FROM pgr_dijkstraVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
ARRAY[6, 3, 6]) WHERE path_id != 1
UNION
SELECT 1 AS path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost FROM pgr_trsp(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
6, 3)),
with_seq AS (
SELECT row_number() over(ORDER BY path_id, path_seq) AS seq, *
FROM solutions),
aggregation AS (SELECT seq, SUM(cost) OVER(ORDER BY seq) AS route_agg_cost FROM with_seq)
SELECT with_seq.*, COALESCE(route_agg_cost, 0) AS route_agg_cost
FROM with_seq LEFT JOIN aggregation ON (with_seq.seq = aggregation.seq + 1);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 6 | 3 | 6 | 4 | 1 | 0 | 0
2 | 1 | 2 | 6 | 3 | 7 | 10 | 1 | 1 | 1
3 | 1 | 3 | 6 | 3 | 8 | 12 | 1 | 2 | 2
4 | 1 | 4 | 6 | 3 | 12 | 13 | 1 | 3 | 3
5 | 1 | 5 | 6 | 3 | 17 | 15 | 1 | 4 | 4
6 | 1 | 6 | 6 | 3 | 16 | 9 | 1 | 5 | 5
7 | 1 | 7 | 6 | 3 | 11 | 8 | 1 | 6 | 6
8 | 1 | 8 | 6 | 3 | 7 | 7 | 1 | 7 | 7
9 | 1 | 9 | 6 | 3 | 3 | -1 | 0 | 8 | 8
10 | 2 | 1 | 3 | 6 | 3 | 7 | 1 | 0 | 8
11 | 2 | 2 | 3 | 6 | 7 | 4 | 1 | 1 | 9
12 | 2 | 3 | 3 | 6 | 6 | -2 | 0 | 2 | 10
(12 rows)
Getting the same result as pgr_trspVia:
SELECT * FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[6, 3, 6]);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 6 | 3 | 6 | 4 | 1 | 0 | 0
2 | 1 | 2 | 6 | 3 | 7 | 10 | 1 | 1 | 1
3 | 1 | 3 | 6 | 3 | 8 | 12 | 1 | 2 | 2
4 | 1 | 4 | 6 | 3 | 12 | 13 | 1 | 3 | 3
5 | 1 | 5 | 6 | 3 | 17 | 15 | 1 | 4 | 4
6 | 1 | 6 | 6 | 3 | 16 | 9 | 1 | 5 | 5
7 | 1 | 7 | 6 | 3 | 11 | 8 | 1 | 6 | 6
8 | 1 | 8 | 6 | 3 | 7 | 7 | 1 | 7 | 7
9 | 1 | 9 | 6 | 3 | 3 | -1 | 0 | 8 | 8
10 | 2 | 1 | 3 | 6 | 3 | 7 | 1 | 0 | 8
11 | 2 | 2 | 3 | 6 | 7 | 4 | 1 | 1 | 9
12 | 2 | 3 | 3 | 6 | 6 | -2 | 0 | 2 | 10
(12 rows)
- Ejemplo 8:
Sometimes
U_turn_on_edgeflag is ignored when is set tofalse.
The first step, doing a pgr_dijkstraVia - Propuesto does consider not making a U turn on the same edge. But the path \(16 \rightarrow 13\) (Rows 4 and 5) is restricted and the result is using it.
SELECT * FROM pgr_dijkstraVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
ARRAY[6, 7, 6], U_turn_on_edge => false);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 6 | 7 | 6 | 4 | 1 | 0 | 0
2 | 1 | 2 | 6 | 7 | 7 | -1 | 0 | 1 | 1
3 | 2 | 1 | 7 | 6 | 7 | 8 | 1 | 0 | 1
4 | 2 | 2 | 7 | 6 | 11 | 9 | 1 | 1 | 2
5 | 2 | 3 | 7 | 6 | 16 | 16 | 1 | 2 | 3
6 | 2 | 4 | 7 | 6 | 15 | 3 | 1 | 3 | 4
7 | 2 | 5 | 7 | 6 | 10 | 2 | 1 | 4 | 5
8 | 2 | 6 | 7 | 6 | 6 | -2 | 0 | 5 | 6
(8 rows)
When executing the pgr_trsp - Proposed algorithm for the conflicting path, there is
no U_turn_on_edge flag.
SELECT 1 AS path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost FROM pgr_trsp(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
7, 6);
path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
---------+----------+-----------+---------+------+------+------+----------
1 | 1 | 7 | 6 | 7 | 4 | 1 | 0
1 | 2 | 7 | 6 | 6 | -1 | 0 | 1
(2 rows)
Therefore the result ignores the U_turn_on_edge flag when set to false.
SELECT * FROM pgr_trspVia(
$$SELECT id, source, target, cost, reverse_cost FROM edges$$,
$$SELECT path, cost FROM restrictions$$,
ARRAY[6, 7, 6], U_turn_on_edge => false);
seq | path_id | path_seq | start_vid | end_vid | node | edge | cost | agg_cost | route_agg_cost
-----+---------+----------+-----------+---------+------+------+------+----------+----------------
1 | 1 | 1 | 6 | 7 | 6 | 4 | 1 | 0 | 0
2 | 1 | 2 | 6 | 7 | 7 | -1 | 0 | 1 | 1
3 | 2 | 1 | 7 | 6 | 7 | 4 | 1 | 0 | 1
4 | 2 | 2 | 7 | 6 | 6 | -2 | 0 | 1 | 2
(4 rows)
Ver también¶
Índices y tablas