[Cartoweb-users] Pgdijkstra Directed Map

[Aileen Baylon]

Hi all,

I've been tinkering with Cartoweb, PostGIS & Pgdijkstra for quite some time 
now.

My questions are

1. How do you use the PostgreSQL shortest_path function so that it would 
help you create a directed route?
ex.
SELECT * FROM shortest_path('SELECT id, source, target, cost FROM 
major_roads_edges', 815, 750, true, false);

2. How do you update the cost of the table using update_cost_from_distance 
if you have an existing distance in that table?

3. What exactly is create_graph_tables for? Is it not the function that 
would fill the edges and vertices tables of the resulting graph? The 
assign_vertex_id function is to fill the columns source_id and target_id 
right? But if I don't execute the assign_vertex_id function since I already 
have a source ID and target ID, why is it that I get the error?

Much help will be appreciated!

Aileen





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