Final edge pheromone update in ACO::updatePHEROMONES about aco HOT 3 CLOSED

Hello there,

Can you elaborate more on that? The loops at https://github.com/diogo-fernan/aco/blob/master/src/ACO.cpp#L288-L293 and https://github.com/diogo-fernan/aco/blob/master/src/ACO.cpp#L167-L169 respectively iterate through all pheromone values and edges.

from aco.

Hi,

The array ROUTE is of length NUMCITIES. So for example, Say we have 3 cities and an ant found route 1->2->3 as feasible route. ROUTE will now be 1, 2, 3 https://github.com/diogo-fernan/aco/blob/master/src/ACO.cpp#L167 will iterate over indices 0 and 1 and add edge weight for edges 1->2 and 2->3 only. But afaik, we should also take the weight of edge 3->1 in consideration. Similarly, https://github.com/diogo-fernan/aco/blob/master/src/ACO.cpp#L281 will not update DELTAPHEROMONES for 3->1. This will be 0. What do you think?

from aco.

As far as I remember the algorithm finds an iterative solution to the shortest path between a starting point and destination. So, in your example, 3->1 would not make sense as it is an inverse path and goes back to the origin. Please see "Computational Intelligence: An Introduction" (first edition from 2002) by Andries Engelbrecht for more information as it provides the theory for the algorithm.

from aco.