Hello list,
Does anybody know tutorial or more detailed information about the use of weighted costs?
I only know that:
http://workshop.pgrouting.org/chapters/advanced.html
Thanks
Pedro
On 3/16/2012 8:12 AM, Pedro Costa wrote:
Hello list,
Does anybody know tutorial or more detailed information about the use of
weighted costs?
I only know that:
http://workshop.pgrouting.org/chapters/advanced.html
Cost is just a positive value (negative edge cost are not allow). You can use distance as a cost, or time as a cost, or turn angle as a cost, or anything you want that makes sense for what you are modelling. The issues is what are you modelling and and what do you want to take into account and can you model that factor as a cost or a component of the cost.
For example, you could convert all costs into some increase number of seconds to traverse from node A to node B. then you could model the distance and average speed as time. If you had an attribute at a node the indicated a traffic light or stop sign, you could add some additional average wait time to the edges passing through that node. If you had an attribute say the road had lots of potholes, you could assume some lower average speed, etc.
You have to transform the things you are modelling into some unit or unitless value as a cost.
-Steve W