[Cartoweb-users] pgdijsktra help

[I B Adams]

Hi, 

I have followed the user guide in setting up the pgdijkstra tables etc.
Subsequently I have a the 3 tables sheffield_roads, sheffield_roads_edges and
sheffield_roads_vertices.

The sheffield_roads_edges table looks like this 

id;source;target;cost;reverse_cost
1;1;2;0.000916630721722411;
2;3;4;0.000553553068824753;
3;5;6;0.000667707188817009;
4;7;8;0.000453705598377561;
5;9;10;0.000834583135466098;
6;11;12;0.000687784995473152;
7;13;14;0.000501129733700344;
8;15;16;0.00319198299650822;
9;17;18;0.000127581346596178;

When I try and retrieve the shortest path using

SELECT shortest_path FROM shortest_path('SELECT * FROM sheffield_roads_edges',
1, 2, false, false)

I get ERROR:  Error computing path: Source vertex not found.

Now I have read that the source id and target id are the ones shown in the
sheffield_roads_edges table which is what I have provided, yet it still doesnt
work. I have also tried to select the ids from the sheffield_road_vertices
using the actually vertices Id's (some big integers). Does Anyone have any
ideas???