pgrouting：地理空间路由

pgRouting 是 Postgres 以及 PostGIS 扩展，增加了地理空间路由功能。

pgRouting 的核心功能是一组路径寻找算法，包括：

🌐 The core functionality of pgRouting is a set of path finding algorithms including:

所有节点对最短路径，约翰逊算法
全对最短路径，弗洛伊德-沃肖算法
最短路径 A*
双向 Dijkstra 最短路径
双向A*最短路径
最短路径迪杰斯特拉
驾驶距离
K 最短路径，多条备选路径
K-Dijkstra，一对多最短路径
推销员
转向限制最短路径（TRSP）

启用扩展 #

🌐 Enable the extension

在仪表板中转到数据库页面。
点击侧边栏的扩展。
搜索 pgrouting 并启用这个扩展。

示例 #

🌐 Example

例如，我们将使用 pgRouting 的 pgr_TSPeuclidean 函数，从一些 PostGIS 坐标来解决旅行推销员问题。

🌐 As an example, we'll solve the traveling salesperson problem using the pgRouting's pgr_TSPeuclidean function from some PostGIS coordinates.

旅行商问题的总结是，给定一组城市坐标，要求找出一条经过每个城市的路径，并使总行程距离最短。

🌐 A summary of the traveling salesperson problem is, given a set of city coordinates, solve for a path that goes through each city and minimizes the total distance traveled.

首先我们用一些 X、Y 坐标填充一个表格

🌐 First we populate a table with some X, Y coordinates

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create table wi29 (
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  id bigint,
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  x float,
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  y float,
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  geom gis.geometry
6
);
7
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insert into wi29 (id, x, y)
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values
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  (1,20833.3333,17100.0000),
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  (2,20900.0000,17066.6667),
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  (3,21300.0000,13016.6667),
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  (4,21600.0000,14150.0000),
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  (5,21600.0000,14966.6667),
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  (6,21600.0000,16500.0000),
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  (7,22183.3333,13133.3333),
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  (8,22583.3333,14300.0000),
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  (9,22683.3333,12716.6667),
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  (10,23616.6667,15866.6667),
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  (11,23700.0000,15933.3333),
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  (12,23883.3333,14533.3333),
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  (13,24166.6667,13250.0000),
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  (14,25149.1667,12365.8333),
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  (15,26133.3333,14500.0000),
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  (16,26150.0000,10550.0000),
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  (17,26283.3333,12766.6667),
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  (18,26433.3333,13433.3333),
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  (19,26550.0000,13850.0000),
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  (20,26733.3333,11683.3333),
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  (21,27026.1111,13051.9444),
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  (22,27096.1111,13415.8333),
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  (23,27153.6111,13203.3333),
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  (24,27166.6667,9833.3333),
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  (25,27233.3333,10450.0000),
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  (26,27233.3333,11783.3333),
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  (27,27266.6667,10383.3333),
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  (28,27433.3333,12400.0000),
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  (29,27462.5000,12992.2222);

接下来我们用 pgr_TSPeuclidean 函数来找出最佳路径。

🌐 Next we use the pgr_TSPeuclidean function to find the best path.

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select
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    *
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from
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     pgr_TSPeuclidean($$select * from wi29$$)

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seq | node |       cost       |     agg_cost     
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-----+------+------------------+------------------
3
   1 |    1 |                0 |                0
4
   2 |    2 |  74.535614157127 |  74.535614157127
5
   3 |    6 | 900.617093380362 | 975.152707537489
6
   4 |   10 | 2113.77757765045 | 3088.93028518793
7
   5 |   11 | 106.718669615254 | 3195.64895480319
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   6 |   12 | 1411.95293791574 | 4607.60189271893
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   7 |   13 | 1314.23824873744 | 5921.84014145637
10
   8 |   14 | 1321.76283931305 | 7243.60298076942
11
   9 |   17 | 1202.91366735569 |  8446.5166481251
12
  10 |   18 | 683.333268292684 | 9129.84991641779
13
  11 |   15 | 1108.05137466134 | 10237.9012910791
14
  12 |   19 | 772.082339448903 |  11009.983630528
15
  13 |   22 | 697.666150054665 | 11707.6497805827
16
  14 |   23 | 220.141999627513 | 11927.7917802102
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  15 |   21 | 197.926372783442 | 12125.7181529937
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  16 |   29 | 440.456596290771 | 12566.1747492844
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  17 |   28 | 592.939989005405 | 13159.1147382898
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  18 |   26 | 648.288376333318 | 13807.4031146231
21
  19 |   20 | 509.901951359278 | 14317.3050659824
22
  20 |   25 | 1330.83095428717 | 15648.1360202696
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  21 |   27 |  74.535658878487 | 15722.6716791481
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  22 |   24 | 559.016994374947 |  16281.688673523
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  23 |   16 | 1243.87392358622 | 17525.5625971092
26
  24 |    9 |  4088.0585364911 | 21613.6211336004
27
  25 |    7 |  650.85409697993 | 22264.4752305803
28
  26 |    3 | 891.004385199336 | 23155.4796157796
29
  27 |    4 | 1172.36699411442 |  24327.846609894
30
  28 |    8 | 994.708187806297 | 25322.5547977003
31
  29 |    5 | 1188.01888359478 | 26510.5736812951
32
  30 |    1 | 2266.91173136004 | 28777.4854126552

资源 #

🌐 Resources

官方 pgRouting 文档