Re: [Boost-users] How do I do reverse routing?

Subject: Re: [Boost-users] How do I do reverse routing?
From: Stephen Woodbridge (woodbri_at_[hidden])
Date: 2010-05-13 14:40:03

Jeremiah Willcock wrote:
> On Wed, 12 May 2010, Stephen Woodbridge wrote:
> 
>> Hi all,
>>
>> A Dijkstra solution builds the tree outward from a source node.
>> Is there and easy was to change the sense of the route so the 
>> calculated result is based on a tree inward to the a sink node?
>>
>> Is there an example of this anywhere? I could not find one.
> 
> There is a reverse_graph adapter.  Would that do what you want?

Jeremiah,

Thanks I missed that. It may work, I need to think about the use case a 
little. There are two use cases that come quickly to mind:

1. driving distance/time/cost to a location like a store, to see what 
coverage area say a 10, 20, 30 min drive time TO the store represents.

2. when doing bi-directional routing, the routing from the destination 
needs to be reversed sense from the routing from the source.

My initial concern is that the reverse_graph adapter creates a new 
adjacency list and while that may work for small graphs it is not likely 
a good solution for a say North America or Europe sized graph.

My thinking was that the process of routing is searching for nodes that 
I can go to from my current location and that reverse routing is just 
searching for nodes that I could come from. I suppose that to be able to 
do that efficiently you have to have an adjacency list that supports that.

I will think about this and try some examples when I get a chance. Let 
me know if you can think of a better way to tackle this problem.

Thanks,
   -Steve