我正在尝试用5个送货司机来解决车辆路线问题。我正在使用Haversine和lat-long来计算距离矩阵。我是OR工具的新手，因此下面是vrp示例。
问题在于out 0f 5驱动程序仅为2个驱动程序生成了路由，这些路由非常长。我想生成多个较短的路由，以便利用所有驱动程序。可以请问我是否设置了一些错误的约束条件。
有人可以解释一下如何在Google或工具中设置“距离”维度和SetGlobalSpanCostCoefficient。这是代码和输出。
from __future__ import print_function
import pandas as pd
import numpy as np
import googlemaps
import math
from ortools.constraint_solver import routing_enums_pb2
from ortools.constraint_solver import pywrapcp
gmaps = googlemaps.Client(key='API Key')
def calculate_geocodes():
df = pd.read_csv("banglore_zone.csv")
df['lat'] = pd.Series(np.repeat(0, df.size), dtype=float)
df['long'] = pd.Series(np.repeat(0, df.size), dtype=float)
result = np.zeros([df.size, 2])
for index, row in df.iterrows():
# print(row['Address'])
geocode_result = gmaps.geocode(row['Address'])[0]
lat = (geocode_result['geometry']['location']['lat'])
lng = (geocode_result['geometry']['location']['lng'])
result[index] = lat, lng
df.lat[index] = lat
df.long[index] = lng
print("First step", df)
coords = df.as_matrix(columns=['lat', 'long'])
return coords, df
def calculate_distance_matrix(coordinates, gmaps):
distance_matrix = np.zeros(
(np.size(coordinates, 0), np.size(coordinates, 0))) # create an empty matrix for distance between all locations
for index in range(0, np.size(coordinates, 0)):
src = coordinates[index]
for ind in range(0, np.size(coordinates, 0)):
dst = coordinates[ind]
distance_matrix[index, ind] = distance(src[0], src[1], dst[0], dst[1])
return distance_matrix
def distance(lat1, long1, lat2, long2):
# Note: The formula used in this function is not exact, as it assumes
# the Earth is a perfect sphere.
# Mean radius of Earth in miles
radius_earth = 3959
# Convert latitude and longitude to
# spherical coordinates in radians.
degrees_to_radians = math.pi / 180.0
phi1 = lat1 * degrees_to_radians
phi2 = lat2 * degrees_to_radians
lambda1 = long1 * degrees_to_radians
lambda2 = long2 * degrees_to_radians
dphi = phi2 - phi1
dlambda = lambda2 - lambda1
a = haversine(dphi) + math.cos(phi1) * math.cos(phi2) * haversine(dlambda)
c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
d = radius_earth * c
return d
def haversine(angle):
h = math.sin(angle / 2) ** 2
return h
def create_data_model(distance_matrix, number_of_vehicles, depot):
"""Stores the data for the problem."""
data = {}
data['distance_matrix'] = distance_matrix
print(distance_matrix)
data['num_vehicles'] = number_of_vehicles
data['depot'] = depot
return data
def print_solution(data, manager, routing, solution, address_dataframe):
"""Prints solution on console."""
max_route_distance = 0
for vehicle_id in range(data['num_vehicles']):
index = routing.Start(vehicle_id)
plan_output = 'Route for vehicle {}:\n'.format(vehicle_id)
route_distance = 0
while not routing.IsEnd(index):
plan_output += ' {} ---> '.format(address_dataframe.iloc[manager.IndexToNode(index), 0])
previous_index = index
index = solution.Value(routing.NextVar(index))
route_distance += routing.GetArcCostForVehicle(
previous_index, index, vehicle_id)
plan_output += '{}\n'.format(manager.IndexToNode(index))
plan_output += 'Distance of the route: {}m\n'.format(route_distance)
print(plan_output)
max_route_distance = max(route_distance, max_route_distance)
print('Maximum of the route distances: {}m'.format(max_route_distance))
def main():
coordinates, address_dataframe = calculate_geocodes()
distance_matrix = calculate_distance_matrix(coordinates, gmaps)
data = create_data_model(distance_matrix, 5, 0)
# Create the routing index manager.
manager = pywrapcp.RoutingIndexManager(
len(data['distance_matrix']), data['num_vehicles'], data['depot'])
# Create Routing Model.
routing = pywrapcp.RoutingModel(manager)
# Create and register a 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.RegisterTransitCallback(distance_callback)
# Define cost of each arc.
routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)
# Add Distance constraint.
dimension_name = 'Distance'
routing.AddDimension(
transit_callback_index,
0, # no slack
80, # vehicle maximum travel distance
True, # start cumul to zero
dimension_name)
distance_dimension = routing.GetDimensionOrDie(dimension_name)
distance_dimension.SetGlobalSpanCostCoefficient(100)
# Setting first solution heuristic.
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
search_parameters.local_search_metaheuristic = (
routing_enums_pb2.LocalSearchMetaheuristic.GUIDED_LOCAL_SEARCH)
search_parameters.time_limit.seconds = 120
search_parameters.log_search = False
# Solve the problem.
solution = routing.SolveWithParameters(search_parameters)
# Print solution on console.
if solution:
print_solution(data, manager, routing, solution, address_dataframe)
if __name__ == '__main__':
main()
距离矩阵和输出为-
> [[ 0. 0.31543319 3.36774402 ... 8.79765925 8.94261055
> 8.83759758] [ 0.31543319 0. 3.09418962 ... 8.81074289 8.95034082
> 8.84901702] [ 3.36774402 3.09418962 0. ... 10.87348059 10.97329493
> 10.89962072] ... [ 8.79765925 8.81074289 10.87348059 ... 0. 0.20726879
> 0.06082994] [ 8.94261055 8.95034082 10.97329493 ... 0.20726879 0.
> 0.1465572 ] [ 8.83759758 8.84901702 10.89962072 ... 0.06082994 0.1465572
> 0. ]] Route for vehicle 0: 3Embed software 10th Cross St, RBI Colony, Ganganagar, Bengaluru, Karnataka 560024 ---> 0 Distance of
> the route: 0m
>
> Route for vehicle 1: 3Embed software 10th Cross St, RBI Colony,
> Ganganagar, Bengaluru, Karnataka 560024 ---> 0 Distance of the route:
> 0m
>
> Route for vehicle 2: 3Embed software 10th Cross St, RBI Colony,
> Ganganagar, Bengaluru, Karnataka 560024 ---> Sindhi High School,
> Kempapura ---> Hoppers stop Building No.12, Krishnaja Avenue, Near
> Kogilu Cross, International Airport Road, Yelahanka, Bengaluru --->
> Kempegowda International Airport Bengaluru ---> mvit International
> Airport Road, Hunasamaranahalli, Yelahanka, Krishnadeveraya Nagar,
> Bengaluru ---> Canadian International School 4 & 20, Manchenahalli,
> Yelahanka, Bengaluru ---> brick factory RMZ Galleria, Office Block,
> Ground Floor, B.B. Road, Yelahanka ---> Jakkur Aerodrome Bellary
> Road, Post, Yelahanka, Bengaluru, Karnataka ---> Godrej Platinum
> International Airport Road, Hebbal, Bengaluru, Karnataka ---> Vidya
> Niketan School 30, Kempapura Main Road, Kempapura, Hebbal, Bengaluru,
> Karnataka ---> Atria Institute of Technology, 1st Main Rd, Ags
> Colony, Anandnagar, Hebbal, Bengaluru, Karnataka ---> 0 Distance of
> the route: 26m
>
> Route for vehicle 3: 3Embed software 10th Cross St, RBI Colony,
> Ganganagar, Bengaluru, Karnataka 560024 ---> Caffe cofee day CBI road
> banglore ---> 0 Distance of the route: 0m
>
> Route for vehicle 4: 3Embed software 10th Cross St, RBI Colony,
> Ganganagar, Bengaluru, Karnataka 560024 ---> RT Nagar Police station
> ---> bus stop mekhri circle banglore ---> Truffles 80 Feet Road, Jaladarsini Layout, Sanjaynagar Banglore ---> BEL circle banglore
> ---> Paragon Outlet Shivapura, Peenya, Bengaluru ---> Taj vivanta Yeshwantpur, Bengaluru ---> Orion Mall A Block, Brigade Gateway, Dr
> Rajkumar Rd, Malleshwaram, Bengaluru ---> brand factory Malleshwaram
> Banglore ---> Mantri Square Mall, Sampige Road, Malleshwaram,
> Bengaluru, Karnataka ---> Krantivira Sangolli Rayanna Bengaluru, M.G.
> Railway Colony, Majestic, Bengaluru ---> UB city banglore --->
> Brigade road banglore ---> MG Road metro station Banglore --->
> commercial street bangalore ---> Infantry Road, Beside Prestige
> Building, Tasker Town, Shivaji Nagar, Bengaluru, Karnataka --->
> Garuda Mall Magrath Rd, Ashok Nagar, Bengaluru ---> Brand Factory -
> Home Town Above HomeTown, Vanshee Towers, Survey No.92/4 3rd and 4th
> Floors, Outer Ring Rd, Marathahalli, Bengaluru ---> KLM Shopping
> Mall, Marathahalli Bridge Marathahalli ---> Favourite Shop HAL Old
> Airport Rd, Subbaiah Reddy Colony, Marathahalli Village, Marathahalli,
> Bengaluru ---> Max RPR Plaza, Varthur Rd, Marathahalli, Bengaluru
> ---> Pick 'n' Move Shop No. 102, Ground Floor, Varthur Rd, Marathahalli Village, Marathahalli, Bengaluru ---> Lotto Shoes 45/2,
> Varthur Rd, Marathahalli Village, Marathahalli, Bengaluru, Karnataka
> ---> The Raymond Shop Opp. Mga Hospital, Marathalli Main Road Near Ring Road Junction, Bengaluru, Karnataka ---> chinnaswamy stadium
> banglore ---> fun cinemas cunningham road Banglore ---> Cant station
> banglore ---> Radhakrishna Theatre 25, 1st Main Rd, Mattdahally, RT
> Nagar, Bengaluru ---> Presidency School Near R T Nagar, HMT Layout,
> Bengaluru, Karnataka ---> 0 Distance of the route: 20m
>
> Maximum of the route distances: 26m
答案 0 :(得分：0)
您应该减少车辆的最大行驶距离。目前，您将其设置为80。 而您的路线距离是20和26。
routing.AddDimension(
transit_callback_index,
0, # no slack
80, # vehicle maximum travel distance
True, # start cumul to zero
dimension_name)
答案 1 :(得分：0)
您可以使用全球跨度成本，这将减少任何车辆行驶的最长路线。
例如。在距离维度上使用它，例如distance_dimension.SetGlobalSpanCostCoefficient()。
传递一个高整数值作为参数，该值大于所有成本的总和。尝试将其设置为1000左右。