def main() -> None: """ Entry point of the program. """ # Parse command line arguments args = parse_args() # Instantiate the data problem data = load_data_model(args.path) # Create the Routing Index Manager and Routing Model manager = RoutingIndexManager(data["num_locations"], data["num_vehicles"], data["depot"]) routing = RoutingModel(manager) # Define weights of edges weight_callback_index = routing.RegisterTransitCallback( create_weight_callback(manager, data)) routing.SetArcCostEvaluatorOfAllVehicles(weight_callback_index) # Add capacity constraints demand_callback = create_demand_callback(manager, data) demand_callback_index = routing.RegisterUnaryTransitCallback( demand_callback) add_capacity_constraints(routing, manager, data, demand_callback_index) # Add time window constraints time_callback_index = routing.RegisterTransitCallback( create_time_callback(manager, data)) add_time_window_constraints(routing, manager, data, time_callback_index) # Set first solution heuristic (cheapest addition) search_params = DefaultRoutingSearchParameters() search_params.first_solution_strategy = FirstSolutionStrategy.PATH_CHEAPEST_ARC if args.gls: search_params.local_search_metaheuristic = ( LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH) # NOTE: Since Guided Local Search could take a very long time, we set a # reasonable time limit search_params.time_limit.seconds = 30 if args.verbose: search_params.log_search = True # Solve the problem assignment = routing.SolveWithParameters(search_params) if not assignment: print("No solution found.") return # Print the solution print_solution(data, routing, manager, assignment) # Export network and route graphs if args.export_network_graph: draw_network_graph(args.export_network_graph, data) if args.export_route_graph: draw_route_graph(args.export_route_graph, data, routing, manager, assignment)
def solve(self, indices_to_visit: List[int] = None) -> Dict[str, Any]: """Finds the optimal order of facilities to minimize distance. Parameters ---------- indices_to_visit : List[int] The list of indices corresponding to the desired facilities to visit Returns ------- Dict[str, Any] Soltution dictionary with keys: - 'objective', set to objective value (minified distance) - 'order', instructions for the order of facilities to visit """ if indices_to_visit is None: indices_to_visit = list(range(len(self.matrix))) # make sure home location is in the listed, and that the list is sorted if self.home_index not in indices_to_visit: indices_to_visit.append(self.home_index) indices_to_visit.sort() data = self._create_data_model(indices_to_visit) # create routing index manager manager = RoutingIndexManager(len(data['distance_matrix']), data['num_vehicles'], data['home']) # create routing model routing = RoutingModel(manager) def distance_callback(from_index, to_index): # returns distance between two nodes from_node = manager.IndexToNode(from_index) to_node = manager.IndexToNode(to_index) dist = data['distance_matrix'][from_node][to_node] return dist transit_callback_index = routing.RegisterTransitCallback( distance_callback) # define cost of each arc routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index) # set first solution heuristic search_params = pywrapcp.DefaultRoutingSearchParameters() search_params.first_solution_strategy = ( routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC) # solve problem assignment = routing.SolveWithParameters(search_params) return self._extract_solution(manager, routing, assignment, indices_to_visit)
def _solve(self, routing: RoutingModel, search_parameters: RoutingSearchParameters, initial_routes) -> Assignment: if initial_routes is None: solution = routing.SolveWithParameters(search_parameters) else: routing.CloseModelWithParameters(search_parameters) initial_solution = routing.ReadAssignmentFromRoutes( initial_routes, True) solution = routing.SolveFromAssignmentWithParameters( initial_solution, search_parameters) return solution
def main(): """ Entry point of the program. """ # Parse command line arguments args = parse_args() #Crafted data : coordinates = [[0.848307, 0.32357132], [0.53917086, 0.862489], [0.28499496, 0.7470896], [0.66891015, 0.07388902], [0.6514969, 0.4077109], [0.782356, 0.28167558], [0.2601446, 0.9196638], [0.3402847, 0.62080956], [0.3920853, 0.8653455], [0.79114413, 0.09456837], [0.11343169, 0.73570406]] Distance_matrix = list() for j in range(len(coordinates)): l = list() for i in range(len(coordinates)): l.append(distance(coordinates[j], coordinates[i])) Distance_matrix.append(l) data = dict() data['weights'] = Distance_matrix data['service_times'] = [0, 1, 0.5, 1, 1, 0.5, 2, 2, 2, 0.5, 2] data['demands'] = [ 0, 0.25, 0.2, 0.1, 0.2, 0.35, 0.15, 0.3, 0.15, 0.15, 0.3 ] data['time_windows'] = [[0, 9], [0, 5], [5, 9], [0, 9], [0, 9], [0, 9], [0, 5], [5, 9], [5, 9], [0, 5], [0, 9]] data['vehicle_capacities'] = [1, 1, 1] data['depot'] = 0 data['num_locations'] = 11 data['num_vehicles'] = 3 # Instantiate the data problem #data = load_data_model(args.path) # Create the Routing Index Manager and Routing Model manager = RoutingIndexManager(data['num_locations'], data['num_vehicles'], data['depot']) routing = RoutingModel(manager) # Define weight of each edge weight_callback_index = routing.RegisterTransitCallback( create_weight_callback(manager, data)) routing.SetArcCostEvaluatorOfAllVehicles(weight_callback_index) # Add capacity constraints demand_callback = create_demand_callback(manager, data) demand_callback_index = routing.RegisterUnaryTransitCallback( demand_callback) add_capacity_constraints(routing, manager, data, demand_callback_index) # Add time window constraints time_callback_index = routing.RegisterTransitCallback( create_time_callback(manager, data)) add_time_window_constraints(routing, manager, data, time_callback_index) # Set first solution heuristic (cheapest addition) search_params = DefaultRoutingSearchParameters() # pylint: disable=no-member search_params.first_solution_strategy = FirstSolutionStrategy.PATH_CHEAPEST_ARC if args.gls: # pylint: disable=no-member search_params.local_search_metaheuristic = LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH # NOTE: Since Guided Local Search could take a very long time, we set a reasonable time # limit search_params.time_limit.seconds = 30 if args.verbose: search_params.log_search = True # Solve the problem assignment = routing.SolveWithParameters(search_params) if not assignment: print('No solution found.') return # Print the solution print_solution(Distance_matrix, data, routing, manager, assignment) # Draw network and route graphs """if args.graph:
For other options, see the link below https://developers.google.com/optimization/routing/routing_options#first_sol_options """ search_params = DefaultRoutingSearchParameters() search_params.first_solution_strategy = FirstSolutionStrategy.PATH_CHEAPEST_ARC if args.gls: search_params.local_search_metaheuristic = LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH # NOTE: Since Guided Local Search could take a very long time, we set a reasonable time limit search_params.time_limit.seconds = 30 if args.verbose: search_params.log_search = True # Solve the problem assignment = routing.SolveWithParameters(search_params) if routing.status() == 1 and assignment: t2 = time() # Print the solution best_score = None best_score = print_solution(data, routing, manager, assignment) print(f'Measured Execute time: {round(t2-t1, 6)}sec') if args.write_csv is not None: with open(args.write_csv, 'a') as f: f.write(f'{t2-t1},{best_score/1e4}\n') # Draw network and route graphs if args.graph: from visualize import draw_network_graph, draw_route_graph # draw_network_graph(data)