{"action":"created","issue":{"url":"https://api.github.com/repos/pgRouting/pgrouting/issues/296","labels_url":"https://api.github.com/repos/pgRouting/pgrouting/issues/296/labels{/name}","comments_url":"https://api.github.com/repos/pgRouting/pgrouting/issues/296/comments","events_url":"https://api.github.com/repos/pgRouting/pgrouting/issues/296/events","html_url":"https://github.com/pgRouting/pgrouting/issues/296","id":59623336,"number":296,"title":"pgr_astar returns one null route ","user":{"login":"noenest","id":11290584,"avatar_url":"https://avatars.githubusercontent.com/u/11290584?v=3","gravatar_id":"","url":"https://api.github.com/users/noenest","html_url":"https://github.com/noenest","followers_url":"https://api.github.com/users/noenest/followers","following_url":"https://api.github.com/users/noenest/following{/other_user}","gists_url":"https://api.github.com/users/noenest/gists{/gist_id}","starred_url":"https://api.github.com/users/noenest/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/noenest/subscriptions","organizations_url":"https://api.github.com/users/noenest/orgs","repos_url":"https://api.github.com/users/noenest/repos","events_url":"https://api.github.com/users/noenest/events{/privacy}","received_events_url":"https://api.github.com/users/noenest/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2015-03-03T10:36:21Z","updated_at":"2015-03-04T11:35:12Z","closed_at":"2015-03-04T11:35:12Z","body":"Dear developers,\r\n\r\nWe have installed pgRouting to perform  searches on the European cartography.\r\n\r\nAfter successfully installing the software and the cartography (version details below), we perform a simple query using the A* algorithm to find the shortest path between two nodes in different cities within the same country. Unfortunately, it not working. The query follows:\r\n\r\n```\r\nSELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_astar(\r\n    'SELECT id, source, target, cost, x1, y1, x2, y2, reverse_cost FROM eu_2po_4pgr \r\n        WHERE ST_dwithin(geom_way::geography, (SELECT geography(ST_makeLine(geom_way)) FROM vista_vertice_table WHERE source IN (8324560, 14246280)), 500)',\r\n    8324560, 14246280, false, false);\r\n```\r\n\r\nThe result is always:\r\n\r\n```\r\npsql:pruebas/prueba31-astar.sql:1: ERROR:  Error computing path: (null)\r\n```\r\n\r\nThe same problem appears with bidirectional A*, but not with Dijkstra or bidirectional Dijkstra.\r\n\r\nWe are using Ubuntu 14, with PostgreSQL 9.3.6, postgis 2.1.2, and pgrouting 2.0.0. Our system has 32Gb of RAM, and the configuration file for PostgreSQL has been created using pgtune.\r\n\r\nIt is very important for our research to solve this issue. Any help will be greatly appreciated.\r\n\r\nThank you very much!"},"comment":{"url":"https://api.github.com/repos/pgRouting/pgrouting/issues/comments/77142969","html_url":"https://github.com/pgRouting/pgrouting/issues/296#issuecomment-77142969","issue_url":"https://api.github.com/repos/pgRouting/pgrouting/issues/296","id":77142969,"user":{"login":"noenest","id":11290584,"avatar_url":"https://avatars.githubusercontent.com/u/11290584?v=3","gravatar_id":"","url":"https://api.github.com/users/noenest","html_url":"https://github.com/noenest","followers_url":"https://api.github.com/users/noenest/followers","following_url":"https://api.github.com/users/noenest/following{/other_user}","gists_url":"https://api.github.com/users/noenest/gists{/gist_id}","starred_url":"https://api.github.com/users/noenest/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/noenest/subscriptions","organizations_url":"https://api.github.com/users/noenest/orgs","repos_url":"https://api.github.com/users/noenest/repos","events_url":"https://api.github.com/users/noenest/events{/privacy}","received_events_url":"https://api.github.com/users/noenest/received_events","type":"User","site_admin":false},"created_at":"2015-03-04T11:35:12Z","updated_at":"2015-03-04T11:35:12Z","body":"I have some questions.\r\n\r\nAs to the node numbers, I got the following results for multiple queries: \r\n\r\n- difference between (max(nodeid) - min(nodeid)) and count(nodeid) when the nodes are in very distant cities within the same country:\r\n\r\n(25478853 - 168719) - 4526 = 25305608 \r\n\r\n- difference between (max(nodeid) - min(nodeid)) and count(nodeid) when the nodes are in nearby cities within the same country:\r\n\r\n(23459170 - 2775613) - 607 = 20682950\r\n\r\n- difference between (max(nodeid) - min(nodeid)) and count(nodeid) when the nodes are in the same city:\r\n\r\n(24464701 - 2775613) - 1114 = 21687974\r\n\r\nIn the first two cases mentioned error occurs. In the latter case the query returns the path .\r\n\r\nI dont know how interpret this result or how try renumbering nodes and that achievement with this.\r\n\r\nOn the other hand, I tried pgr_trsp() and works, but the result for the cost is always zero. Why this happens? It has also happened to me with pgr_bdDijkstra. \r\n\r\nAnd finally, why the A * algorithm has these problems and Dijsktra algorithm runs without modifying the base query?\r\n\r\nThanks!!"}}