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ortools-clone/examples/notebook/constraint_solver/vrp_capacity.ipynb
2022-06-27 15:42:26 +02:00

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{
"cells": [
{
"cell_type": "markdown",
"id": "google",
"metadata": {},
"source": [
"##### Copyright 2022 Google LLC."
]
},
{
"cell_type": "markdown",
"id": "apache",
"metadata": {},
"source": [
"Licensed under the Apache License, Version 2.0 (the \"License\");\n",
"you may not use this file except in compliance with the License.\n",
"You may obtain a copy of the License at\n",
"\n",
" http://www.apache.org/licenses/LICENSE-2.0\n",
"\n",
"Unless required by applicable law or agreed to in writing, software\n",
"distributed under the License is distributed on an \"AS IS\" BASIS,\n",
"WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
"See the License for the specific language governing permissions and\n",
"limitations under the License.\n"
]
},
{
"cell_type": "markdown",
"id": "basename",
"metadata": {},
"source": [
"# vrp_capacity"
]
},
{
"cell_type": "markdown",
"id": "link",
"metadata": {},
"source": [
"<table align=\"left\">\n",
"<td>\n",
"<a href=\"https://colab.research.google.com/github/google/or-tools/blob/main/examples/notebook/constraint_solver/vrp_capacity.ipynb\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/colab_32px.png\"/>Run in Google Colab</a>\n",
"</td>\n",
"<td>\n",
"<a href=\"https://github.com/google/or-tools/blob/main/ortools/constraint_solver/samples/vrp_capacity.py\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/github_32px.png\"/>View source on GitHub</a>\n",
"</td>\n",
"</table>"
]
},
{
"cell_type": "markdown",
"id": "doc",
"metadata": {},
"source": [
"First, you must install [ortools](https://pypi.org/project/ortools/) package in this colab."
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "install",
"metadata": {},
"outputs": [],
"source": [
"!pip install ortools"
]
},
{
"cell_type": "markdown",
"id": "description",
"metadata": {},
"source": [
"\n",
"Capacited Vehicles Routing Problem (CVRP).\n"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "code",
"metadata": {},
"outputs": [],
"source": [
"from ortools.constraint_solver import routing_enums_pb2\n",
"from ortools.constraint_solver import pywrapcp\n",
"\n",
"\n",
"def create_data_model():\n",
" \"\"\"Stores the data for the problem.\"\"\"\n",
" data = {}\n",
" data['distance_matrix'] = [\n",
" [\n",
" 0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354,\n",
" 468, 776, 662\n",
" ],\n",
" [\n",
" 548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674,\n",
" 1016, 868, 1210\n",
" ],\n",
" [\n",
" 776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164,\n",
" 1130, 788, 1552, 754\n",
" ],\n",
" [\n",
" 696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822,\n",
" 1164, 560, 1358\n",
" ],\n",
" [\n",
" 582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708,\n",
" 1050, 674, 1244\n",
" ],\n",
" [\n",
" 274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628,\n",
" 514, 1050, 708\n",
" ],\n",
" [\n",
" 502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856,\n",
" 514, 1278, 480\n",
" ],\n",
" [\n",
" 194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320,\n",
" 662, 742, 856\n",
" ],\n",
" [\n",
" 308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662,\n",
" 320, 1084, 514\n",
" ],\n",
" [\n",
" 194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388,\n",
" 274, 810, 468\n",
" ],\n",
" [\n",
" 536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764,\n",
" 730, 388, 1152, 354\n",
" ],\n",
" [\n",
" 502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114,\n",
" 308, 650, 274, 844\n",
" ],\n",
" [\n",
" 388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194,\n",
" 536, 388, 730\n",
" ],\n",
" [\n",
" 354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0,\n",
" 342, 422, 536\n",
" ],\n",
" [\n",
" 468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536,\n",
" 342, 0, 764, 194\n",
" ],\n",
" [\n",
" 776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274,\n",
" 388, 422, 764, 0, 798\n",
" ],\n",
" [\n",
" 662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730,\n",
" 536, 194, 798, 0\n",
" ],\n",
" ]\n",
" data['demands'] = [0, 1, 1, 2, 4, 2, 4, 8, 8, 1, 2, 1, 2, 4, 4, 8, 8]\n",
" data['vehicle_capacities'] = [15, 15, 15, 15]\n",
" data['num_vehicles'] = 4\n",
" data['depot'] = 0\n",
" return data\n",
"\n",
"\n",
"def print_solution(data, manager, routing, solution):\n",
" \"\"\"Prints solution on console.\"\"\"\n",
" print(f'Objective: {solution.ObjectiveValue()}')\n",
" total_distance = 0\n",
" total_load = 0\n",
" for vehicle_id in range(data['num_vehicles']):\n",
" index = routing.Start(vehicle_id)\n",
" plan_output = 'Route for vehicle {}:\\n'.format(vehicle_id)\n",
" route_distance = 0\n",
" route_load = 0\n",
" while not routing.IsEnd(index):\n",
" node_index = manager.IndexToNode(index)\n",
" route_load += data['demands'][node_index]\n",
" plan_output += ' {0} Load({1}) -> '.format(node_index, route_load)\n",
" previous_index = index\n",
" index = solution.Value(routing.NextVar(index))\n",
" route_distance += routing.GetArcCostForVehicle(\n",
" previous_index, index, vehicle_id)\n",
" plan_output += ' {0} Load({1})\\n'.format(manager.IndexToNode(index),\n",
" route_load)\n",
" plan_output += 'Distance of the route: {}m\\n'.format(route_distance)\n",
" plan_output += 'Load of the route: {}\\n'.format(route_load)\n",
" print(plan_output)\n",
" total_distance += route_distance\n",
" total_load += route_load\n",
" print('Total distance of all routes: {}m'.format(total_distance))\n",
" print('Total load of all routes: {}'.format(total_load))\n",
"\n",
"\n",
"def main():\n",
" \"\"\"Solve the CVRP problem.\"\"\"\n",
" # Instantiate the data problem.\n",
" data = create_data_model()\n",
"\n",
" # Create the routing index manager.\n",
" manager = pywrapcp.RoutingIndexManager(len(data['distance_matrix']),\n",
" data['num_vehicles'], data['depot'])\n",
"\n",
" # Create Routing Model.\n",
" routing = pywrapcp.RoutingModel(manager)\n",
"\n",
"\n",
" # Create and register a transit callback.\n",
" def distance_callback(from_index, to_index):\n",
" \"\"\"Returns the distance between the two nodes.\"\"\"\n",
" # Convert from routing variable Index to distance matrix NodeIndex.\n",
" from_node = manager.IndexToNode(from_index)\n",
" to_node = manager.IndexToNode(to_index)\n",
" return data['distance_matrix'][from_node][to_node]\n",
"\n",
" transit_callback_index = routing.RegisterTransitCallback(distance_callback)\n",
"\n",
" # Define cost of each arc.\n",
" routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)\n",
"\n",
"\n",
" # Add Capacity constraint.\n",
" def demand_callback(from_index):\n",
" \"\"\"Returns the demand of the node.\"\"\"\n",
" # Convert from routing variable Index to demands NodeIndex.\n",
" from_node = manager.IndexToNode(from_index)\n",
" return data['demands'][from_node]\n",
"\n",
" demand_callback_index = routing.RegisterUnaryTransitCallback(\n",
" demand_callback)\n",
" routing.AddDimensionWithVehicleCapacity(\n",
" demand_callback_index,\n",
" 0, # null capacity slack\n",
" data['vehicle_capacities'], # vehicle maximum capacities\n",
" True, # start cumul to zero\n",
" 'Capacity')\n",
"\n",
" # Setting first solution heuristic.\n",
" search_parameters = pywrapcp.DefaultRoutingSearchParameters()\n",
" search_parameters.first_solution_strategy = (\n",
" routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC)\n",
" search_parameters.local_search_metaheuristic = (\n",
" routing_enums_pb2.LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH)\n",
" search_parameters.time_limit.FromSeconds(1)\n",
"\n",
" # Solve the problem.\n",
" solution = routing.SolveWithParameters(search_parameters)\n",
"\n",
" # Print solution on console.\n",
" if solution:\n",
" print_solution(data, manager, routing, solution)\n",
"\n",
"\n",
"main()\n",
"\n"
]
}
],
"metadata": {},
"nbformat": 4,
"nbformat_minor": 5
}