',python,optimization,routing,pyomo"/>

首页 > 解决方案 > Pyomo:ValueError:约束“VehicleNumCapRule”没有正确的值。成立 ''

问题描述

同样,作为 pyomo 爱好者和 Python 的狂热爱好者,我试图在 pyomo 中编写带有时间窗(vrptw)的车辆路线问题。我创建 time_window 参数为:

model.time_windows = Param(model.V)     # model.V is the set of nodes

在我的 .dat 文件中,我声明了如下参数:

param Time_windows: a b :=

0   1400 1500
1   0000 2400
2   0000 2400
3   0700 2400
4   0000 2400
5   0000 0700
6   0700 2400
7   0700 2400
8   0000 0700
9   0000 2400
10  0000 2400
11  0000 2400
12  0700 2400
13  0000 2400
14  0000 0700
15  0000 0800
16  0000 2400
17  0000 2400
18  0700 1200
19  0000 2400
;

但是,当我运行我的脚本时,我陷入了这个错误:

ERROR: Constructing component 'time_windows' from data={(9, 'a'): 0, (18,
'b'): 1200, (13, 'b'): 2400, (17, 'a'): 0, (6, 'a'): 700, (2, 'a'): 0,
(19, 'b'): 2400, (4, 'b'): 2400, (14, 'b'): 700, (10, 'a'): 0, (12, 'b'):
2400, (18, 'a'): 700, (1, 'b'): 2400, (3, 'a'): 700, (9, 'b'): 2400, (11,
'a'): 0, (17, 'b'): 2400, (14, 'a'): 0, (0, 'b'): 1500, (4, 'a'): 0, (12,
'a'): 700, (8, 'b'): 700, (3, 'b'): 2400, (7, 'b'): 2400, (16, 'b'): 2400,
(15, 'a'): 0, (11, 'b'): 2400, (6, 'b'): 2400, (5, 'a'): 0, (13, 'a'): 0,
(0, 'a'): 1400, (15, 'b'): 800, (8, 'a'): 0, (7, 'a'): 700, (16, 'a'): 0,
(2, 'b'): 2400, (19, 'a'): 0, (1, 'a'): 0, (10, 'b'): 2400, (5, 'b'): 700}
failed:
    RuntimeError: Failed to set value for param=time_windows, index=(9,
    'a'), value=0.
    source error message="Index '(9, 'a')' is not valid for indexed component
    'time_windows'"
Traceback (most recent call last):
  File "main.py", line 16, in <module>
instance = model.create_instance('data.dat')
  File "/usr/local/lib/python2.7/dist-packages/pyomo/core/base/PyomoModel.py", line 723, in create_instance
profile_memory=profile_memory )
  File "/usr/local/lib/python2.7/dist-packages/pyomo/core/base/PyomoModel.py", line 806, in load
profile_memory=profile_memory)
  File "/usr/local/lib/python2.7/dist-packages/pyomo/core/base/PyomoModel.py", line 870, in _load_model_data
self._initialize_component(modeldata, namespaces, component_name, profile_memory)
  File "/usr/local/lib/python2.7/dist-packages/pyomo/core/base/PyomoModel.py", line 925, in _initialize_component
declaration.construct(data)
  File "/usr/local/lib/python2.7/dist-packages/pyomo/core/base/param.py", line 858, in construct
% (self.name, str(key), str(val), str(msg)) )
RuntimeError: Failed to set value for param=time_windows, index=(9, 'a'), value=0.
source error message="Index '(9, 'a')' is not valid for indexed component 'time_windows'"

有人可以告诉我发生了什么。提前致谢

编辑:这是包含 model.V 的部分

model.Vo = Set()                           
model.Vf = Set()                           
model.Vc = Set()                           
model.Vfc = model.Vf | model.Vc             
model.V = model.Vo | model.Vf | model.Vc   # set of nodes

在 .dat 文件中我有:

set Vo := 0;
set Vf := 1 2;
set Vc := 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19;

标签: pythonoptimizationroutingpyomo

解决方案


model.time_windows您的示例代码尝试使用二维数据初始化一维参数。

model.time_windows = Param(model.V, ['a', 'b'])应该工作。


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