CODEWITHSUNDEEP
a-starpgrouting
Esdras Assikidana
Esdras Assikidana

Reputation: 15

Custom heuristic on pgrouting pgr_astar function

So i'm using pgrouting to compute shortest path on transit network, The cost of my graph is time, but the graph isn't "time dependent" - which means my arcs are available at every hour everyday, the cost is not the distance between station but the time it take to move from one point to another. I figured by doing the computation that pgr_astar (and even pgr_bdAstar) is slower than pgr_dijkstra. I thought it might be a heuristic problem. My questions is :

Is there a way to edit pgr_astar to insert your own heuristi

Upvotes: 1

Views: 96

Answers (1)

Zegarek
Zegarek

Reputation: 26467

It's open-source, so yes you can, as long as you don't mind some C/C++: here. Still, what you likely want is one of the 6 built-in options:

             switch (m_heuristic) {
                 case 0:
                     current = 0;
                     break;
                 case 1:
                     current = std::fabs((std::max)(dx, dy)) * m_factor;
                     break;
                 case 2:
                     current = std::fabs((std::min)(dx, dy)) * m_factor;
                     break;
                 case 3:
                     current = (dx * dx + dy * dy) * m_factor * m_factor;
                     break;
                 case 4:
                     current = std::sqrt(dx * dx + dy * dy) * m_factor;
                     break;
                 case 5:
                     current = (std::fabs(dx) + std::fabs(dy)) * m_factor;
                     break;
                 default:
                     current = 0;
             }

All of which are fairly simple as it is.

Upvotes: 0

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