[pgrouting-dev] Shortest Path with conditional cost

[Julien-Samuel Lacroix]

Hi Steve,

I took a look at the code, but I must admit I'm a bit lost in the code 
of this branch. There's only one sql function called pgr_vrpOneDepot 
that takes order, vehicule, cost and depot sql statement. Can you give 
me an example of this in action?

Is there any documentation from the GSoC project?

I feel like my problem is the reverse of this. I have a bunch of 
vehicule and only one order to deliver at one or more depot. I want to 
be able to use one vehicule in my network, but not two. The reason 
behind this reasoning, that there may be more than one type of vehicule 
(carpool, bike, city bus, etc) and you can use more than one of them in 
a single ride, but not twice the same type in a single ride (Note that I 
oversimplified my explanation here). Anyway, I'll take a look at the VRP 
code to get ideas.

Julien

On 14-03-10 09:12 PM, Stephen Woodbridge wrote:
> Julien,
>
> This is called the Dial-A-Ride problem. It is a common VRP (Vehicle
> Routing Problem).  You could also use a PDP (pickup and delivery
> problem) to solve this where your packages are you people and the
> delivery point is the destination and the start point it the driver's
> location. Both of these are well defined problems and can be solved
> using a TABU search.
>
> We have a basic VRP solver that was developed last year in GSoC but it
> is for a single depot multiple package delivery with time windows
> problem. It uses a TABU search.
>
> https://github.com/pgRouting/pgrouting/tree/gsoc-vrp/src/vrp_basic
>
> -Steve
>
> On 3/10/2014 8:53 PM, Julien-Samuel Lacroix wrote:
>> Hello,
>>
>> I'm trying to get my head around a networking building problem and
>> wonder if it would be possible to have conditional cost depending on the
>> type of segment (or nodes) we crossed to get there?
>>
>> An example would be:
>> Each line segment have a cost and a type (A, B or C). You need to
>> calculate the shortest path from one node 1 to node 35, but can only use
>> one segment of type C.
>>
>> Would this be possible?
>> What kind of modification would this need?
>>
>> My current solution would be to calculate the total cost using every
>> single type C segment in my area, but in the long run, I fear this won't
>> scale.
>>
>> I'm currently building a carpooling portal and I get the carpool offers
>> as segments and nodes in my DB. I should not allow users to plan a trip
>> combining 2 different offers as this quickly becomes a logistical
>> nightmare.
>>
>> Best regards,
>> Julien
>>
>>
>
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-- 
Julien-Samuel Lacroix
T: +1 418-696-5056 #202
Mapgears
http://www.mapgears.com/