def path_weight_to(other)
      shortest_path_to(other,:method => :djikstra).map{|edge| edge.weight.to_f}.sum
    end
def path_weight_to(other)
      shortest_path_to(other,:method => :djikstra).map{|edge| edge.weight.to_f}.sum
    end
+other+ The target node to find a route to
 Gives the path weight as a float of the shortest path to the other