routing: Add VRP Solution Callback (#3300)
This commit is contained in:
Corentin Le Molgat
@@ -419,6 +419,7 @@ test_cpp_constraint_solver_samples: \
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rcpp_vrp_pickup_delivery_fifo \
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rcpp_vrp_pickup_delivery_lifo \
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rcpp_vrp_resources \
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rcpp_vrp_solution_callback \
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rcpp_vrp_starts_ends \
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rcpp_vrp_time_windows \
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rcpp_vrp_with_time_limit
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@@ -325,6 +325,7 @@ test_dotnet_constraint_solver_samples: \
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rdotnet_VrpPickupDeliveryFifo \
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rdotnet_VrpPickupDeliveryLifo \
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rdotnet_VrpResources \
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rdotnet_VrpSolutionCallback \
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rdotnet_VrpStartsEnds \
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rdotnet_VrpTimeWindows \
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rdotnet_VrpWithTimeLimit
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@@ -304,6 +304,7 @@ test_java_constraint_solver_samples: \
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rjava_VrpPickupDeliveryFifo \
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rjava_VrpPickupDeliveryLifo \
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rjava_VrpResources \
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rjava_VrpSolutionCallback \
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rjava_VrpStartsEnds \
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rjava_VrpTimeWindows \
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rjava_VrpWithTimeLimit
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@@ -138,6 +138,7 @@ test_python_constraint_solver_samples: \
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rpy_vrp_pickup_delivery_fifo \
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rpy_vrp_pickup_delivery_lifo \
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rpy_vrp_resources \
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rpy_vrp_solution_callback \
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rpy_vrp_starts_ends \
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rpy_vrp_time_windows \
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rpy_vrp_tokens \
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200
ortools/constraint_solver/samples/VrpSolutionCallback.cs
Normal file
200
ortools/constraint_solver/samples/VrpSolutionCallback.cs
Normal file
@@ -0,0 +1,200 @@
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// Copyright 2010-2022 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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// [START import]
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using System;
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using System.Collections.Generic;
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using Google.OrTools.ConstraintSolver;
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using Google.Protobuf.WellKnownTypes; // Duration
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// [END import]
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/// <summary>
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/// Minimal Vehicle Routing Problem (VRP).
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/// The search stop after improving the solution 15 times or after 5 seconds.
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/// </summary>
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public class VrpSolutionCallback
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{
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// [START data_model]
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class DataModel
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{
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public long[,] DistanceMatrix = {
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{ 0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468, 776, 662 },
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{ 548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016, 868, 1210 },
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{ 776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130, 788, 1552, 754 },
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{ 696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164, 560, 1358 },
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{ 582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050, 674, 1244 },
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{ 274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514, 1050, 708 },
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{ 502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514, 1278, 480 },
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{ 194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662, 742, 856 },
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{ 308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320, 1084, 514 },
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{ 194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274, 810, 468 },
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{ 536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730, 388, 1152, 354 },
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{ 502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650, 274, 844 },
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{ 388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536, 388, 730 },
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{ 354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342, 422, 536 },
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{ 468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342, 0, 764, 194 },
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{ 776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422, 764, 0, 798 },
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{ 662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536, 194, 798, 0 }
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};
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public int VehicleNumber = 4;
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public int Depot = 0;
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};
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// [END data_model]
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// [START solution_callback_printer]
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/// <summary>
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/// Print the solution.
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/// </summary>
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static void printSolution(ref RoutingIndexManager routingManager, ref RoutingModel routingModel)
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{
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Console.WriteLine($"Solution objective: {routingModel.CostVar().Value()}:");
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// Inspect solution.
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long totalDistance = 0;
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for (int i = 0; i < routingManager.GetNumberOfVehicles(); ++i)
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{
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Console.WriteLine("################");
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Console.WriteLine($"Route for Vehicle {i}:");
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long routeDistance = 0;
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long index = routingModel.Start(i);
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while (routingModel.IsEnd(index) == false)
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{
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Console.Write($" {routingManager.IndexToNode(index)} ->");
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long previousIndex = index;
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index = routingModel.NextVar(index).Value();
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routeDistance += routingModel.GetArcCostForVehicle(previousIndex, index, 0);
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}
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Console.WriteLine($" {routingManager.IndexToNode(index)}");
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Console.WriteLine($"Distance of the route: {routeDistance}m");
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totalDistance += routeDistance;
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}
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Console.WriteLine($"Total Distance of all routes: {totalDistance}m");
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}
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// [END solution_callback_printer]
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// [START solution_callback]
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class SolutionCallback {
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public long[] objectives;
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private RoutingIndexManager routingManager;
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private RoutingModel routingModel;
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private long maxSolution;
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private long counter;
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public SolutionCallback(
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ref RoutingIndexManager manager,
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ref RoutingModel routing,
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in long limit)
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{
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routingManager = manager;
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routingModel = routing;;
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maxSolution = limit;
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counter = 0;
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objectives = new long[maxSolution];
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}
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public void Run() {
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long objective = routingModel.CostVar().Value();
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if(counter == 0 || objective < objectives[counter-1]) {
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objectives[counter] = objective;
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printSolution(ref routingManager, ref routingModel);
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counter++;
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}
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if(counter >= maxSolution) {
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routingModel.solver().FinishCurrentSearch();
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}
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}
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};
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// [END solution_callback]
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public static void Main(String[] args)
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{
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// Instantiate the data problem.
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// [START data]
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DataModel data = new DataModel();
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// [END data]
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// Create Routing Index Manager
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// [START index_manager]
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RoutingIndexManager routingManager =
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new RoutingIndexManager(data.DistanceMatrix.GetLength(0), data.VehicleNumber, data.Depot);
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// [END index_manager]
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// Create Routing Model.
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// [START routing_model]
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RoutingModel routingModel = new RoutingModel(routingManager);
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// [END routing_model]
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// Create and register a transit callback.
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// [START transit_callback]
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int transitCallbackIndex = routingModel.RegisterTransitCallback(
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(long fromIndex, long toIndex) =>
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{
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// Convert from routing variable Index to
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// distance matrix NodeIndex.
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var fromNode = routingManager.IndexToNode(fromIndex);
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var toNode = routingManager.IndexToNode(toIndex);
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return data.DistanceMatrix[fromNode, toNode];
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});
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// [END transit_callback]
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// Define cost of each arc.
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// [START arc_cost]
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routingModel.SetArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
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// [END arc_cost]
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// Add Distance constraint.
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// [START distance_constraint]
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routingModel.AddDimension(
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transitCallbackIndex,
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0, // no slack
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3000, // vehicle maximum travel distance
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true, // start cumul to zero
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"Distance");
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RoutingDimension distanceDimension = routingModel.GetMutableDimension("Distance");
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distanceDimension.SetGlobalSpanCostCoefficient(100);
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// [END distance_constraint]
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// Attach a solution callback.
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// [START attach_callback]
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SolutionCallback solutionCallback = new SolutionCallback(ref routingManager, ref routingModel, /*max_solution=*/15);
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routingModel.AddAtSolutionCallback(solutionCallback.Run);
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// [END attach_callback]
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// Setting first solution heuristic.
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// [START parameters]
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RoutingSearchParameters searchParameters =
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operations_research_constraint_solver.DefaultRoutingSearchParameters();
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searchParameters.FirstSolutionStrategy = FirstSolutionStrategy.Types.Value.PathCheapestArc;
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searchParameters.LocalSearchMetaheuristic = LocalSearchMetaheuristic.Types.Value.GuidedLocalSearch;
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searchParameters.TimeLimit = new Duration { Seconds = 5 };
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// [END parameters]
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// Solve the problem.
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// [START solve]
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Assignment solution = routingModel.SolveWithParameters(searchParameters);
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// [END solve]
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// Print solution on console.
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// [START print_solution]
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if(solution != null)
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{
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Console.WriteLine($"Best objective: {solutionCallback.objectives[^1]}");
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}
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else
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{
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Console.WriteLine("No solution found !");
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}
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// [END print_solution]
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}
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}
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// [END program]
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200
ortools/constraint_solver/samples/VrpSolutionCallback.java
Normal file
200
ortools/constraint_solver/samples/VrpSolutionCallback.java
Normal file
@@ -0,0 +1,200 @@
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// Copyright 2010-2022 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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package com.google.ortools.constraintsolver.samples;
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// [START import]
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import com.google.ortools.Loader;
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import com.google.ortools.constraintsolver.Assignment;
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import com.google.ortools.constraintsolver.FirstSolutionStrategy;
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import com.google.ortools.constraintsolver.LocalSearchMetaheuristic;
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import com.google.ortools.constraintsolver.RoutingDimension;
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import com.google.ortools.constraintsolver.RoutingIndexManager;
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import com.google.ortools.constraintsolver.RoutingModel;
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import com.google.ortools.constraintsolver.RoutingSearchParameters;
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import com.google.ortools.constraintsolver.main;
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import com.google.protobuf.Duration;
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import java.util.logging.Logger;
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// [END import]
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/** Minimal VRP.*/
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public class VrpSolutionCallback {
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private static final Logger logger = Logger.getLogger(VrpSolutionCallback.class.getName());
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// [START data_model]
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static class DataModel {
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public final long[][] distanceMatrix = {
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{0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468, 776, 662},
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{548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016, 868, 1210},
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{776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130, 788, 1552, 754},
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{696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164, 560, 1358},
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{582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050, 674, 1244},
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{274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514, 1050, 708},
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{502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514, 1278, 480},
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{194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662, 742, 856},
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{308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320, 1084, 514},
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{194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274, 810, 468},
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{536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730, 388, 1152, 354},
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{502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650, 274, 844},
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{388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536, 388, 730},
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{354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342, 422, 536},
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{468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342, 0, 764, 194},
|
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{776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422, 764, 0, 798},
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{662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536, 194, 798, 0},
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};
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public final int vehicleNumber = 4;
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public final int depot = 0;
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}
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// [END data_model]
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// [START solution_callback_printer]
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/// @brief Print the solution.
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static void printSolution(RoutingIndexManager routingManager, RoutingModel routingModel) {
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// Solution cost.
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logger.info("################");
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logger.info("Solution objective : " + routingModel.costVar().value());
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// Inspect solution.
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long totalDistance = 0;
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for (int i = 0; i < routingManager.getNumberOfVehicles(); ++i) {
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logger.info("Route for Vehicle " + i + ":");
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long routeDistance = 0;
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long index = routingModel.start(i);
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String route = "";
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while (!routingModel.isEnd(index)) {
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route += routingManager.indexToNode(index) + " -> ";
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long previousIndex = index;
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index = routingModel.nextVar(index).value();
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routeDistance += routingModel.getArcCostForVehicle(previousIndex, index, i);
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}
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logger.info(route + routingManager.indexToNode(index));
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logger.info("Distance of the route: " + routeDistance + "m");
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totalDistance += routeDistance;
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}
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logger.info("Total distance of all routes: " + totalDistance + "m");
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}
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// [END solution_callback_printer]
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// [START solution_callback]
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static class SolutionCallback implements Runnable {
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public final long[] objectives;
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private final RoutingIndexManager routingManager;
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private final RoutingModel routingModel;
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private final int maxSolution;
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private int counter;
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public SolutionCallback(
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final RoutingIndexManager manager,
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final RoutingModel routing,
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int limit)
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{
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routingManager = manager;
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routingModel = routing;
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maxSolution = limit;
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counter = 0;
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objectives = new long[maxSolution];
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}
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@Override
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public void run() {
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long objective = routingModel.costVar().value();
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if(counter == 0 || objective < objectives[counter-1]) {
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objectives[counter] = objective;
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printSolution(routingManager, routingModel);
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counter++;
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}
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if(counter >= maxSolution) {
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routingModel.solver().finishCurrentSearch();
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||||
}
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||||
}
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};
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// [END solution_callback]
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public static void main(String[] args) throws Exception {
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Loader.loadNativeLibraries();
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// Instantiate the data problem.
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// [START data]
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final DataModel data = new DataModel();
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// [END data]
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// Create Routing Index Manager
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// [START index_manager]
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final RoutingIndexManager routingManager =
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new RoutingIndexManager(data.distanceMatrix.length, data.vehicleNumber, data.depot);
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// [END index_manager]
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// Create Routing Model.
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// [START routing_model]
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final RoutingModel routingModel = new RoutingModel(routingManager);
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// [END routing_model]
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// Create and register a transit callback.
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// [START transit_callback]
|
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final int transitCallbackIndex =
|
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routingModel.registerTransitCallback((long fromIndex, long toIndex) -> {
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// Convert from routing variable Index to user NodeIndex.
|
||||
int fromNode = routingManager.indexToNode(fromIndex);
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int toNode = routingManager.indexToNode(toIndex);
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return data.distanceMatrix[fromNode][toNode];
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||||
});
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||||
// [END transit_callback]
|
||||
|
||||
// Define cost of each arc.
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||||
// [START arc_cost]
|
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routingModel.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
|
||||
// [END arc_cost]
|
||||
|
||||
// Add Distance constraint.
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||||
// [START distance_constraint]
|
||||
routingModel.addDimension(
|
||||
transitCallbackIndex,
|
||||
0, // no slack
|
||||
3000, // vehicle maximum travel distance
|
||||
true, // start cumul to zero
|
||||
"Distance");
|
||||
RoutingDimension distanceDimension = routingModel.getMutableDimension("Distance");
|
||||
distanceDimension.setGlobalSpanCostCoefficient(100);
|
||||
// [END distance_constraint]
|
||||
|
||||
// Attach a solution callback.
|
||||
// [START attach_callback]
|
||||
final SolutionCallback solutionCallback = new SolutionCallback(routingManager, routingModel, 15);
|
||||
routingModel.addAtSolutionCallback(solutionCallback);
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||||
// [END attach_callback]
|
||||
|
||||
// Setting first solution heuristic.
|
||||
// [START parameters]
|
||||
RoutingSearchParameters searchParameters =
|
||||
main.defaultRoutingSearchParameters()
|
||||
.toBuilder()
|
||||
.setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_CHEAPEST_ARC)
|
||||
.setLocalSearchMetaheuristic(LocalSearchMetaheuristic.Value.GUIDED_LOCAL_SEARCH)
|
||||
.setTimeLimit(Duration.newBuilder().setSeconds(5).build())
|
||||
.build();
|
||||
// [END parameters]
|
||||
|
||||
// Solve the problem.
|
||||
// [START solve]
|
||||
Assignment solution = routingModel.solveWithParameters(searchParameters);
|
||||
// [END solve]
|
||||
|
||||
// Print solution on console.
|
||||
// [START print_solution]
|
||||
if(solution != null) {
|
||||
logger.info("Best objective: " + solutionCallback.objectives[solutionCallback.objectives.length - 1]);
|
||||
} else {
|
||||
logger.info("No solution found !");
|
||||
}
|
||||
// [END print_solution]
|
||||
}
|
||||
}
|
||||
// [END program]
|
||||
218
ortools/constraint_solver/samples/vrp_solution_callback.cc
Normal file
218
ortools/constraint_solver/samples/vrp_solution_callback.cc
Normal file
@@ -0,0 +1,218 @@
|
||||
// Copyright 2010-2022 Google LLC
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// [START program]
|
||||
// [START import]
|
||||
#include <algorithm>
|
||||
#include <cstdint>
|
||||
#include <functional>
|
||||
#include <sstream>
|
||||
#include <vector>
|
||||
|
||||
#include "ortools/constraint_solver/routing.h"
|
||||
#include "ortools/constraint_solver/routing_enums.pb.h"
|
||||
#include "ortools/constraint_solver/routing_index_manager.h"
|
||||
#include "ortools/constraint_solver/routing_parameters.h"
|
||||
// [END import]
|
||||
|
||||
namespace operations_research {
|
||||
// [START data_model]
|
||||
struct DataModel {
|
||||
const std::vector<std::vector<int64_t>> distance_matrix{
|
||||
{0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468,
|
||||
776, 662},
|
||||
{548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674,
|
||||
1016, 868, 1210},
|
||||
{776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130,
|
||||
788, 1552, 754},
|
||||
{696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822,
|
||||
1164, 560, 1358},
|
||||
{582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708,
|
||||
1050, 674, 1244},
|
||||
{274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514,
|
||||
1050, 708},
|
||||
{502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514,
|
||||
1278, 480},
|
||||
{194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662,
|
||||
742, 856},
|
||||
{308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320,
|
||||
1084, 514},
|
||||
{194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274,
|
||||
810, 468},
|
||||
{536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730,
|
||||
388, 1152, 354},
|
||||
{502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308,
|
||||
650, 274, 844},
|
||||
{388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536,
|
||||
388, 730},
|
||||
{354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342,
|
||||
422, 536},
|
||||
{468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342,
|
||||
0, 764, 194},
|
||||
{776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388,
|
||||
422, 764, 0, 798},
|
||||
{662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536,
|
||||
194, 798, 0},
|
||||
};
|
||||
const int num_vehicles = 4;
|
||||
const RoutingIndexManager::NodeIndex depot{0};
|
||||
};
|
||||
// [END data_model]
|
||||
|
||||
//! @brief Print the solution.
|
||||
//! @param[in] routing_manager Index manager used.
|
||||
//! @param[in] routing_model Routing solver used.
|
||||
// [START solution_callback_printer]
|
||||
void print_solution(
|
||||
const RoutingIndexManager& routing_manager,
|
||||
const RoutingModel& routing_model) {
|
||||
LOG(INFO) << "################";
|
||||
LOG(INFO) << "Solution objective: " << routing_model.CostVar()->Value();
|
||||
int64_t total_distance{0};
|
||||
for (int vehicle_id = 0; vehicle_id < routing_manager.num_vehicles(); ++vehicle_id) {
|
||||
int64_t index = routing_model.Start(vehicle_id);
|
||||
LOG(INFO) << "Route for Vehicle " << vehicle_id << ":";
|
||||
int64_t route_distance{0};
|
||||
std::stringstream route;
|
||||
while (routing_model.IsEnd(index) == false) {
|
||||
route << " " << routing_manager.IndexToNode(index).value() << " ->";
|
||||
int64_t previous_index = index;
|
||||
index = routing_model.NextVar(index)->Value();
|
||||
route_distance += routing_model.GetArcCostForVehicle(previous_index, index,
|
||||
int64_t{vehicle_id});
|
||||
}
|
||||
LOG(INFO) << route.str() << routing_manager.IndexToNode(index).value();
|
||||
LOG(INFO) << "Distance of the route: " << route_distance << "m";
|
||||
total_distance += route_distance;
|
||||
}
|
||||
LOG(INFO) << "Total distance of all routes: " << total_distance << "m";
|
||||
}
|
||||
// [END solution_callback_printer]
|
||||
|
||||
// [START solution_callback]
|
||||
struct SolutionCallback {
|
||||
const RoutingIndexManager& routing_manager;
|
||||
const RoutingModel& routing_model;
|
||||
const int64_t max_solution;
|
||||
|
||||
SolutionCallback(
|
||||
const RoutingIndexManager& manager,
|
||||
const RoutingModel& model,
|
||||
const int64_t max_solution):
|
||||
routing_manager(manager),
|
||||
routing_model(model),
|
||||
max_solution(max_solution) {
|
||||
objectives.reserve(max_solution);
|
||||
};
|
||||
~SolutionCallback() = default;
|
||||
|
||||
void Run() {
|
||||
int64_t objective = routing_model.CostVar()->Value();
|
||||
if(objectives.empty() || objective < objectives.back()) {
|
||||
objectives.push_back(objective);
|
||||
print_solution(routing_manager, routing_model);
|
||||
counter++;
|
||||
}
|
||||
if(counter >= max_solution) {
|
||||
routing_model.solver()->FinishCurrentSearch();
|
||||
}
|
||||
}
|
||||
|
||||
std::vector<int64_t> objectives = {};
|
||||
|
||||
private:
|
||||
int64_t counter = 0;
|
||||
};
|
||||
// [END solution_callback]
|
||||
|
||||
void VrpSolutionCallback() {
|
||||
// Instantiate the data problem.
|
||||
// [START data]
|
||||
DataModel data;
|
||||
// [END data]
|
||||
|
||||
// Create Routing Index Manager.
|
||||
// [START index_manager]
|
||||
RoutingIndexManager routing_manager(data.distance_matrix.size(), data.num_vehicles,
|
||||
data.depot);
|
||||
// [END index_manager]
|
||||
|
||||
// Create Routing Model.
|
||||
// [START routing_model]
|
||||
RoutingModel routing_model(routing_manager);
|
||||
// [END routing_model]
|
||||
|
||||
// Create and register a transit callback.
|
||||
// [START transit_callback]
|
||||
const int transit_callback_index = routing_model.RegisterTransitCallback(
|
||||
[&data, &routing_manager](int64_t from_index, int64_t to_index) -> int64_t {
|
||||
// Convert from routing variable Index to distance matrix NodeIndex.
|
||||
auto from_node = routing_manager.IndexToNode(from_index).value();
|
||||
auto to_node = routing_manager.IndexToNode(to_index).value();
|
||||
return data.distance_matrix[from_node][to_node];
|
||||
});
|
||||
// [END transit_callback]
|
||||
|
||||
// Define cost of each arc.
|
||||
// [START arc_cost]
|
||||
routing_model.SetArcCostEvaluatorOfAllVehicles(transit_callback_index);
|
||||
// [END arc_cost]
|
||||
|
||||
// Add Distance constraint.
|
||||
// [START distance_constraint]
|
||||
routing_model.AddDimension(
|
||||
transit_callback_index,
|
||||
0, // no slack
|
||||
3000, // vehicle maximum travel distance
|
||||
true, // start cumul to zero
|
||||
"Distance");
|
||||
routing_model.GetMutableDimension("Distance")->SetGlobalSpanCostCoefficient(100);
|
||||
// [END distance_constraint]
|
||||
|
||||
// Attach a solution callback.
|
||||
// [START attach_callback]
|
||||
SolutionCallback solution_callback{routing_manager, routing_model, /*max_solution=*/15};
|
||||
routing_model.AddAtSolutionCallback(std::bind(&SolutionCallback::Run, &solution_callback));
|
||||
// [END attach_callback]
|
||||
|
||||
// Setting first solution heuristic.
|
||||
// [START parameters]
|
||||
RoutingSearchParameters search_parameters = DefaultRoutingSearchParameters();
|
||||
search_parameters.set_first_solution_strategy(
|
||||
FirstSolutionStrategy::PATH_CHEAPEST_ARC);
|
||||
search_parameters.set_local_search_metaheuristic(
|
||||
LocalSearchMetaheuristic::GUIDED_LOCAL_SEARCH);
|
||||
search_parameters.mutable_time_limit()->set_seconds(5);
|
||||
// [END parameters]
|
||||
|
||||
// Solve the problem.
|
||||
// [START solve]
|
||||
const Assignment* solution = routing_model.SolveWithParameters(search_parameters);
|
||||
// [END solve]
|
||||
|
||||
// Print solution on console.
|
||||
// [START print_solution]
|
||||
if (solution != nullptr) {
|
||||
LOG(INFO) << "Best objectives: " << std::to_string(solution_callback.objectives.back());
|
||||
} else {
|
||||
LOG(INFO) << "No solution found.";
|
||||
}
|
||||
// [END print_solution]
|
||||
}
|
||||
} // namespace operations_research
|
||||
|
||||
int main(int argc, char** argv) {
|
||||
operations_research::VrpSolutionCallback();
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
// [END program]
|
||||
245
ortools/constraint_solver/samples/vrp_solution_callback.py
Executable file
245
ortools/constraint_solver/samples/vrp_solution_callback.py
Executable file
@@ -0,0 +1,245 @@
|
||||
#!/usr/bin/env python3
|
||||
# Copyright 2010-2022 Google LLC
|
||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||
# you may not use this file except in compliance with the License.
|
||||
# You may obtain a copy of the License at
|
||||
#
|
||||
# http://www.apache.org/licenses/LICENSE-2.0
|
||||
#
|
||||
# Unless required by applicable law or agreed to in writing, software
|
||||
# distributed under the License is distributed on an "AS IS" BASIS,
|
||||
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
# See the License for the specific language governing permissions and
|
||||
# limitations under the License.
|
||||
|
||||
# [START program]
|
||||
"""Simple Vehicles Routing Problem (VRP).
|
||||
|
||||
This is a sample using the routing library python wrapper to solve a VRP
|
||||
problem.
|
||||
|
||||
The solver stop after improving its solution 15 times or after 5 seconds.
|
||||
|
||||
Distances are in meters.
|
||||
"""
|
||||
|
||||
# [START import]
|
||||
from ortools.constraint_solver import routing_enums_pb2
|
||||
from ortools.constraint_solver import pywrapcp
|
||||
# [END import]
|
||||
|
||||
|
||||
# [START data_model]
|
||||
def create_data_model():
|
||||
"""Stores the data for the problem."""
|
||||
data = {}
|
||||
data['distance_matrix'] = [
|
||||
[
|
||||
0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354,
|
||||
468, 776, 662
|
||||
],
|
||||
[
|
||||
548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674,
|
||||
1016, 868, 1210
|
||||
],
|
||||
[
|
||||
776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164,
|
||||
1130, 788, 1552, 754
|
||||
],
|
||||
[
|
||||
696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822,
|
||||
1164, 560, 1358
|
||||
],
|
||||
[
|
||||
582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708,
|
||||
1050, 674, 1244
|
||||
],
|
||||
[
|
||||
274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628,
|
||||
514, 1050, 708
|
||||
],
|
||||
[
|
||||
502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856,
|
||||
514, 1278, 480
|
||||
],
|
||||
[
|
||||
194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320,
|
||||
662, 742, 856
|
||||
],
|
||||
[
|
||||
308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662,
|
||||
320, 1084, 514
|
||||
],
|
||||
[
|
||||
194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388,
|
||||
274, 810, 468
|
||||
],
|
||||
[
|
||||
536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764,
|
||||
730, 388, 1152, 354
|
||||
],
|
||||
[
|
||||
502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114,
|
||||
308, 650, 274, 844
|
||||
],
|
||||
[
|
||||
388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194,
|
||||
536, 388, 730
|
||||
],
|
||||
[
|
||||
354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0,
|
||||
342, 422, 536
|
||||
],
|
||||
[
|
||||
468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536,
|
||||
342, 0, 764, 194
|
||||
],
|
||||
[
|
||||
776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274,
|
||||
388, 422, 764, 0, 798
|
||||
],
|
||||
[
|
||||
662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730,
|
||||
536, 194, 798, 0
|
||||
],
|
||||
]
|
||||
data['num_vehicles'] = 4
|
||||
data['depot'] = 0
|
||||
return data
|
||||
# [END data_model]
|
||||
|
||||
|
||||
# [START solution_callback_printer]
|
||||
def print_solution(
|
||||
routing_manager: pywrapcp.RoutingIndexManager,
|
||||
routing_model: pywrapcp.RoutingModel):
|
||||
"""Prints solution on console."""
|
||||
print('################')
|
||||
print(f'Solution objective: {routing_model.CostVar().Value()}')
|
||||
total_distance = 0
|
||||
for vehicle_id in range(routing_manager.GetNumberOfVehicles()):
|
||||
index = routing_model.Start(vehicle_id)
|
||||
plan_output = f'Route for vehicle {vehicle_id}:\n'
|
||||
route_distance = 0
|
||||
while not routing_model.IsEnd(index):
|
||||
plan_output += f' {routing_manager.IndexToNode(index)} ->'
|
||||
previous_index = index
|
||||
index = routing_model.NextVar(index).Value()
|
||||
route_distance += routing_model.GetArcCostForVehicle(
|
||||
previous_index, index, vehicle_id)
|
||||
plan_output += f' {routing_manager.IndexToNode(index)}\n'
|
||||
plan_output += f'Distance of the route: {route_distance}m\n'
|
||||
print(plan_output)
|
||||
total_distance += route_distance
|
||||
print(f'Total Distance of all routes: {total_distance}m')
|
||||
# [END solution_callback_printer]
|
||||
|
||||
# [START solution_callback]
|
||||
def create_routing_monitor(
|
||||
routing_manager: pywrapcp.RoutingIndexManager,
|
||||
routing_model: pywrapcp.RoutingModel,
|
||||
max_solution: int) -> callable:
|
||||
class RoutingMonitor:
|
||||
def __init__(self,
|
||||
manager: pywrapcp.RoutingIndexManager,
|
||||
model: pywrapcp.RoutingModel,
|
||||
limit: int):
|
||||
self._routing_manager = manager
|
||||
self._routing_model = model
|
||||
self._counter = 0
|
||||
self._counter_limit = limit
|
||||
self.objectives = []
|
||||
|
||||
def __call__(self):
|
||||
objective = int(self._routing_model.CostVar().Value())
|
||||
if not self.objectives or objective < self.objectives[-1]:
|
||||
self.objectives.append(objective)
|
||||
print_solution(self._routing_manager, self._routing_model)
|
||||
self._counter += 1
|
||||
if self._counter > self._counter_limit:
|
||||
self._routing_model.solver().FinishCurrentSearch()
|
||||
return RoutingMonitor(routing_manager, routing_model, max_solution)
|
||||
# [END solution_callback]
|
||||
|
||||
|
||||
def main():
|
||||
"""Entry point of the program."""
|
||||
# Instantiate the data problem.
|
||||
# [START data]
|
||||
data = create_data_model()
|
||||
# [END data]
|
||||
|
||||
# Create the routing index manager.
|
||||
# [START index_manager]
|
||||
manager = pywrapcp.RoutingIndexManager(len(data['distance_matrix']),
|
||||
data['num_vehicles'], data['depot'])
|
||||
# [END index_manager]
|
||||
|
||||
# Create Routing Model.
|
||||
# [START routing_model]
|
||||
routing_model = pywrapcp.RoutingModel(manager)
|
||||
# [END routing_model]
|
||||
|
||||
# Create and register a transit callback.
|
||||
# [START transit_callback]
|
||||
def distance_callback(from_index, to_index):
|
||||
"""Returns the distance between the two nodes."""
|
||||
# Convert from routing variable Index to distance matrix NodeIndex.
|
||||
from_node = manager.IndexToNode(from_index)
|
||||
to_node = manager.IndexToNode(to_index)
|
||||
return data['distance_matrix'][from_node][to_node]
|
||||
|
||||
transit_callback_index = routing_model.RegisterTransitCallback(distance_callback)
|
||||
# [END transit_callback]
|
||||
|
||||
# Define cost of each arc.
|
||||
# [START arc_cost]
|
||||
routing_model.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)
|
||||
# [END arc_cost]
|
||||
|
||||
# Add Distance constraint.
|
||||
# [START distance_constraint]
|
||||
dimension_name = 'Distance'
|
||||
routing_model.AddDimension(
|
||||
transit_callback_index,
|
||||
0, # no slack
|
||||
3000, # vehicle maximum travel distance
|
||||
True, # start cumul to zero
|
||||
dimension_name)
|
||||
distance_dimension = routing_model.GetDimensionOrDie(dimension_name)
|
||||
distance_dimension.SetGlobalSpanCostCoefficient(100)
|
||||
# [END distance_constraint]
|
||||
|
||||
# Attach a solution callback.
|
||||
# [START attach_callback]
|
||||
routing_monitor = create_routing_monitor(manager, routing_model, max_solution=15)
|
||||
routing_model.AddAtSolutionCallback(routing_monitor)
|
||||
# [END attach_callback]
|
||||
|
||||
# Setting first solution heuristic.
|
||||
# [START parameters]
|
||||
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
|
||||
search_parameters.first_solution_strategy = (
|
||||
routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC)
|
||||
search_parameters.local_search_metaheuristic = (
|
||||
routing_enums_pb2.LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH)
|
||||
search_parameters.time_limit.FromSeconds(5)
|
||||
# [END parameters]
|
||||
|
||||
# Solve the problem.
|
||||
# [START solve]
|
||||
solution = routing_model.SolveWithParameters(search_parameters)
|
||||
# [END solve]
|
||||
|
||||
# Print solution on console.
|
||||
# [START print_solution]
|
||||
if solution:
|
||||
print(f'Best objective: {routing_monitor.objectives[-1]}')
|
||||
else:
|
||||
print('No solution found !')
|
||||
# [END print_solution]
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
main()
|
||||
# [END program]
|
||||
Reference in New Issue
Block a user