[pgrouting-users] server closed the connection unexpectedly with
shortest_path when using directed = true
woodbri at swoodbridge.com
Mon May 17 14:09:30 EDT 2010
Charles Galpin wrote:
> Hi Steve
> On May 17, 2010, at 11:03 AM, Stephen Woodbridge wrote:
>> I do not think you should be passing -1 as the reverse cost, what is
>> that supposed to mean? Edge weights should not be negative. If You are
>> just trying to avoid it from taking a reverse edge for testing then
>> set the value to a very large number instead.
> I simply want to force the routing to not support traversing a link in
> reverse (in other words force the routing to follow the only real world
> path). My links are directed (one way).
> According to the following wiki page, a negative cost prevents an edge
> from being inserted into the graph.
OK, it has been a while since I read the docs, so maybe I should go read
them again ;)
> I can see having a large number working by making the cost high, but
> this doesn't seem right.
>> Typically, you should be passing the column that contains the reverse
>> cost and not a constant. In you example above "length" is a column
>> that contains the cost, if your cost and reverse cost are the same and
>> you just want to test a bidirectional graph then you could set you
>> reverse cost to "length" also, like:
>> SELECT gid AS id, source::integer,target::integer, length::double
>> precision AS cost, length::double precision as reverse_cost FROM links
> Doesn't this just say my links are bidirectional and the cost is the
> This is exactly what I don't want :)
More information about the Pgrouting-users