shortestPath(graph, source, target [, opt])
Return an array of IDs of nodes on the shortest path between
source and
target.
source and
target can either be elements or IDs of elements.
opt.weight is an optional function returning a distance between two nodes.
It defaults to
function(u, v) { return 1 }.
If
opt.directed is
true, the algorithm will take link direction into account.
The implementation uses the
joint.alg.Dijkstra plugin internally. Please
refer to the plugin documentation for more information.
