Hello everyone, I am trying out the pgdijkstra library and am having difficulties getting it to work with my test dataset. Included is the sql to load the test dataset, and a SVG and PNG output of what the dataset looks like.
Running this sql works (finding the path from the start of the green line to
the end of the yellow line)
SELECT gid,astext(the_geom) FROM shortest_path_as_geometry('line_test',
(select v.id from line_test_vertices v join line_test g on v.geom_id =
g.source_id where g.ident=1),
(select v.id from line_test_vertices v join line_test g on v.geom_id =
g.target_id where g.ident=3));
outputs
5|"MULTILINESTRING((665249.377865961 5662895.69047619,670545.577160494
5659332.79276896,668812.275573192 5654999.53880071,670449.282627866
5649607.04497354,674589.947530864 5645658.9691358))"
6|"MULTILINESTRING((674589.947530864 5645658.9691358,671701.111552028
5635259.15961199,663419.781746032 5641325.71516755,652634.794091711
5639688.70811287))"
7|"MULTILINESTRING((652634.794091711 5639688.70811287,650708.903439153
5631022.20017637,656486.575396825 5624859.35008818,663227.192680776
5629096.30952381,667560.44664903 5623222.34303351,671315.933421517
5623126.04850088,677767.667107584 5629481.48765432))"
Running this sql does not work (finding the path from the start of the green
line to the end of the red line)
SELECT gid,astext(the_geom) FROM shortest_path_as_geometry('line_test',
(select v.id from line_test_vertices v join line_test g on v.geom_id =
g.source_id where g.ident=1),
(select v.id from line_test_vertices v join line_test g on v.geom_id =
g.target_id where g.ident=4));
outputs
ERROR: Error computing path: No path found
CONTEXT: PL/pgSQL function "shortest_path_as_geometry_internal_id" line 9 at
for over execute statement
PL/pgSQL function "shortest_path_as_geometry" line 24 at for over select rows
Looking at the tables and columns pgdijkstra creates / fills, it seems that
only the start and end vertices of a line are taken into consideration, hence
pgdijkstra thinks that the red line is not connected to the network. Is this
true? If so, any way to get pgdijkstra to work in this situation? Any help /
ideas form seasoned pgdijkstra users is greatly appreciated.
Thank you,
Darren H.
line_test.png
Description: PNG image
BEGIN;
CREATE TABLE "line_test" (gid serial PRIMARY KEY, "ident" int4);
SELECT AddGeometryColumn('','line_test','the_geom','-1','MULTILINESTRING',2);
INSERT INTO "line_test" ("ident",the_geom) VALUES ('1','010500000001000000010200000005000000B3A577C1424D24410CC330EC2B9A55418B948127A376244105BABC32B1965541F0ED178D18692441F4B57BE2759255418299B490E2752441B8D8E0C2318D5541F3C322E53B9624412C5206BE56895541');
INSERT INTO "line_test" ("ident",the_geom) VALUES ('2','010500000001000000010200000004000000F3C322E53B9624412C5206BE56895541F2581D39AA7F2441381537CA2E7F554110044190F73E24411C4EC56D1B8555414F309396B5EA2341AAB8512D82835541');
INSERT INTO "line_test" ("ident",the_geom) VALUES ('3','0105000000010000000102000000070000004F309396B5EA2341AAB8512D82835541A4938FCEA9DB234189B0CF8C0B7B5541A6699A26CD08244145D867D606755541FF0DA762763D2441F43CCF132A795541812EAFE4505F2441D242F4956D735541CF6CE9DDA77C244171A31A83557355410E208F550FAF244178BA355F8A795541');
INSERT INTO "line_test" ("ident",the_geom) VALUES ('4','010500000001000000010200000003000000F2581D39AA7F2441381537CA2E7F5541BB2798C9ACD4244165E0E9767D7D5541C42265606DD5244156CE010488765541');
END;
line_test.svg
Description: image/svg
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