Is there a generic introduction which list what each of the route method
does and why I would what to use it with a given data set/
Dave
--
this http://www.pgrouting.org/docs/foss4g2008/index.html
2012/1/30 Dave Potts <dave.potts@pinan.co.uk>
Is there a generic introduction which list what each of the route method
does and why I would what to use it with a given data set/Dave
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On 1/30/2012 5:26 PM, Dave Potts wrote:
Is there a generic introduction which list what each of the route method
does and why I would what to use it with a given data set/
There is a tutorial
http://www.pgrouting.org/docs/foss4g2008/index.html
and here is my assessment:
Dijkstra solution:
This is a node based solution that converts a graph into a tree and the tree has all nodes that are reachable from the start node. This is used in the driving distance solution and has other applications where you might want the cost to get to multiple node. The default output is to only return that path from the start node to the destination node.
Astar search solution:
This is a modified Dijkstra solver that uses a Heuristic to direct the solver to the destination node. As a result, the graph solution is typically faster the Dijkstra because you only have to solve part of the graph needed to find the solution.
ShootingStar solution:
This is an edge based solver. IT IS CURRENT BROKEN! and as best as I can tell the last version that worked is v1.03. It is current running significantly (2-4x slower than the above two solutions). The reason it was created was because it support turn restrictions.
These are the main three solvers.
We just added a new branch TRSP (turn restricted shortest path) that is (will be) an alternative to ShootingStar. It is a modified Dijkstra solver, that takes turn restrictions and is only slight slower than Dijkstra.
In addition to these there is a TDSP (time dependent shortest path) that I believe is based off of Dijkstra solver, that allows costs to be dynamically selected based on a start time and time along the route, so if you have costs like average speed per time of day, the correct cost can be used when solving the problem.
And we have a couple more Google Summer of Code add-ons to pgrouting that I'm not sure I can do justice to explain.
-Steve