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我正在研究基于教程的 VRP 优化问题。当我添加 subtours 约束时，我得到一个错误。我正在关注本教程：https ://www.youtube.com/watch?v=eMsqsmftWOQ&t=2398s

from docplex.mp.model import Model
mdl = Model('CVRP')

x = mdl.binary_var_dict(arcos, name = 'x')
u = mdl.continuous_var_dict(nodos, ub = Q, name = 'u')
mdl.minimize(mdl.sum(distancia[i,j]*x[i,j] for i,j in arcos))
mdl.add_constraints(mdl.sum(x[i,j] for j in nodos if i!= j) == 1 for i in clientes)
mdl.add_constraints(mdl.sum(x[i,j] for i in nodos if i!= j) == 1 for j in clientes)
mdl.add_indicator_constraints(mdl.indicator_constraint(x[i,j],u[i]+q[j]==u[j]) for i,j in arcos if i!=0 and j!= 0) #This is the line

语境：

clientes = [x for x in range(1, n+1)]
nodos = [0]+clientes
arcos = {(i,j) for i in nodos for j in nodos if i != j}
Q = 15

错误列表是：

C:\Users\Jose Godoy\PycharmProjects\Huevos hermanos\venv\lib\site-packages\docplex\mp\__init__.py:35: RuntimeWarning: docplex is not officially supported on 32 bits. Use it at your own risk.
  warnings.warn("docplex is not officially supported on 32 bits. Use it at your own risk.", RuntimeWarning)
Traceback (most recent call last):

 File "C:/Users/Jose Godoy/PycharmProjects/Huevos hermanos/VRP.py", line 41, in <module>
    mdl.add_indicator_constraints(mdl.indicator_constraint(x[i,j],u[i]+q[j]==u[j]) for i,j in arcos if i!=0 and j!= 0)

File "C:\Users\Jose Godoy\PycharmProjects\Huevos hermanos\venv\lib\site-packages\docplex\mp\model.py", line 3014, in add_indicator_constraints
    ind_indices = self.__engine.create_batch_indicator_constraints(indcts)

  File "C:\Users\Jose Godoy\PycharmProjects\Huevos hermanos\venv\lib\site-packages\docplex\mp\engine.py", line 465, in create_batch_indicator_constraints
    return self.create_batch_cts(indicators)

  File "C:\Users\Jose Godoy\PycharmProjects\Huevos hermanos\venv\lib\site-packages\docplex\mp\engine.py", line 449, in create_batch_cts
    self._increment_cts(len(ct_seq))
TypeError: object of type 'generator' has no len()

我认为公式的语法还可以，与教程相同，所以我认为是库中的问题，因为我收到警告消息

RuntimeWarning: docplex is not officially supported on 32 bits. Use it at your own risk.
  warnings.warn("docplex is not officially supported on 32 bits. Use it at your own risk.", RuntimeWarning)

你知道我该如何解决吗？

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1 回答 1

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我解决了这个问题。我添加了一个

[]

所以这对我有用：

mdl.add_indicator_constraints(mdl.indicator_constraint([x[i,j],u[i]+q[j]==u[j]) for i,j in arcos if i!=0 and j!= 0]) #This is the line
于 2019-06-01T02:31:47.240 回答