Question

I’m wondering if it’s possible to make dynamic edges weights in BGL? I’m writing public transport navigator so except time as weight it would be nice if I can promote actualy using line instead of change at every stop event if it would be 3 minutes faster – this is just inconvenient.

Thanks for your help

edit:
Or maybe there is better library than can do that which I should use?

Answer 1

I’m not entirely clear on what you mean by dynamic… the weights are presumably stored in edge properties; there’s nothing to stop you updating the properties with new values as required.

If you mean that you want the edge weights to be a function-object (or “functor”, if you must) rather than “just a value”, then see this thread on the BGL users list; haven’t tried it myself. Makes me wonder how well various graph algorithms using edge weights deal with the weights changing while they’re in progress (if the functor is called more than once and returns a different value each time)…