Python Pyomo约束声明
begginer对pyomo说,我有一个问题需要对我的约束进行编码 以下是我的输入数据:Python Pyomo约束声明,python,model,constraints,pyomo,Python,Model,Constraints,Pyomo,begginer对pyomo说,我有一个问题需要对我的约束进行编码 以下是我的输入数据: S = ['E', 'L'] #shits N = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] #employee ID D = [1,2,3] #days R = {(1, 'D'): 1, (1, 'N'): 1, (2, 'D'): 1, (2, 'N'): 1, (3, 'D'): 2, (3, 'N'):3} # cover requirement {(day,shif
S = ['E', 'L'] #shits
N = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] #employee ID
D = [1,2,3] #days
R = {(1, 'D'): 1,
(1, 'N'): 1,
(2, 'D'): 1,
(2, 'N'): 1,
(3, 'D'): 2,
(3, 'N'):3} # cover requirement {(day,shift):number of employees required}
我是这样做的:
model.N = Set(initialize = N)
model.S = Set(initialize = S)
model.D = Set(initialize = D)
model.N_S_D = Set(within = model.N * model.S * model.D,
initialize = [(n, s, d) for n in model.N for s in model.S for d in model.D])
决策变量声明:
model.x = Var(model.N_S_D, within=Binary, initialize=0)
约束声明,其中约束为
(在我的模型中,r是r)
除了我得到错误的约束之一:
namererror:name'd'未定义之外,所有单元格都工作正常。给出这个错误,我想知道我的set声明model.N\u S\u D
是否正确。其次,我不清楚如何声明集合覆盖要求(R
),以及我是否应该这样做?谢谢您的代码中有几个问题
- 你的班次不匹配。(见下文我的发言)
- 当您看到“for each”表示法时,您需要为集合或组合集合的每个元素创建一个约束…您要求和的内容需要在求和表达式中,并且您需要循环“for eaches”是一种很好的思考方式。。。我想你疯了
- 您没有正确地表达
sum()
表达式。您需要在求和的对象中定义索引的来源。我建议你在pyomo之外尝试一些关于sum()
的练习题,以便更好地处理它
- 将来,如果您将所有代码以工作(或至少产生错误)的格式粘贴到一个块中,以便有人可以直接复制并处理它,这将更有帮助
下面是两种不同的方法来回答你的问题。首先是使用约束列表
的方法。备选方案使用了一个函数约束组合,我发现这更容易,但两者都可以。。。。只是不要同时包含这两个,因为它们是多余的。:)
生成:
我知道我不想对你说谢谢,但你的回答是如此详细和有益,我想这样做!非常感谢:)
model.C1 = ConstraintList()
for N in model.N_S_D:
const_expr = sum(model.x[(d, s) == R[(d, s)]])
model.C1.add(expr = const_expr)
from pyomo.environ import *
S = ['D', 'N'] #shifts
N = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] #employee ID
D = [1, 2, 3] #days
R = { (1, 'D'): 1,
(1, 'N'): 1,
(2, 'D'): 1,
(2, 'N'): 1,
(3, 'D'): 2,
(3, 'N'): 3} # cover requirement {(day,shift):number of employees required}
model = ConcreteModel('shift schedule')
model.N = Set(initialize = N)
model.S = Set(initialize = S)
model.D = Set(initialize = D)
model.N_S_D = Set(within = model.N * model.S * model.D,
initialize = [(n, s, d) for n in model.N for s in model.S for d in model.D])
model.x = Var(model.N_S_D, within=Binary) #, initialize=0)
model.C1 = ConstraintList()
shift_day_combos = [(s, d) for s in model.S for d in model.D]
for s, d in shift_day_combos:
const_expr = sum(model.x[(n, s, d)] for n in model.N) == R[(d, s)]
model.C1.add(expr = const_expr)
# alternate approach...
def cover_requirement(model, s, d):
return sum(model.x[n, s, d] for n in model.N) == R[d,s]
model.C2 = Constraint(model.S, model.D, rule=cover_requirement)
model.pprint()
...
2 Constraint Declarations
C1 : Size=6, Index=C1_index, Active=True
Key : Lower : Body : Upper : Active
1 : 1.0 : x[0,D,1] + x[1,D,1] + x[2,D,1] + x[3,D,1] + x[4,D,1] + x[5,D,1] + x[6,D,1] + x[7,D,1] + x[8,D,1] + x[9,D,1] : 1.0 : True
2 : 1.0 : x[0,D,2] + x[1,D,2] + x[2,D,2] + x[3,D,2] + x[4,D,2] + x[5,D,2] + x[6,D,2] + x[7,D,2] + x[8,D,2] + x[9,D,2] : 1.0 : True
3 : 2.0 : x[0,D,3] + x[1,D,3] + x[2,D,3] + x[3,D,3] + x[4,D,3] + x[5,D,3] + x[6,D,3] + x[7,D,3] + x[8,D,3] + x[9,D,3] : 2.0 : True
4 : 1.0 : x[0,N,1] + x[1,N,1] + x[2,N,1] + x[3,N,1] + x[4,N,1] + x[5,N,1] + x[6,N,1] + x[7,N,1] + x[8,N,1] + x[9,N,1] : 1.0 : True
5 : 1.0 : x[0,N,2] + x[1,N,2] + x[2,N,2] + x[3,N,2] + x[4,N,2] + x[5,N,2] + x[6,N,2] + x[7,N,2] + x[8,N,2] + x[9,N,2] : 1.0 : True
6 : 3.0 : x[0,N,3] + x[1,N,3] + x[2,N,3] + x[3,N,3] + x[4,N,3] + x[5,N,3] + x[6,N,3] + x[7,N,3] + x[8,N,3] + x[9,N,3] : 3.0 : True
C2 : Size=6, Index=C2_index, Active=True
Key : Lower : Body : Upper : Active
('D', 1) : 1.0 : x[0,D,1] + x[1,D,1] + x[2,D,1] + x[3,D,1] + x[4,D,1] + x[5,D,1] + x[6,D,1] + x[7,D,1] + x[8,D,1] + x[9,D,1] : 1.0 : True
('D', 2) : 1.0 : x[0,D,2] + x[1,D,2] + x[2,D,2] + x[3,D,2] + x[4,D,2] + x[5,D,2] + x[6,D,2] + x[7,D,2] + x[8,D,2] + x[9,D,2] : 1.0 : True
('D', 3) : 2.0 : x[0,D,3] + x[1,D,3] + x[2,D,3] + x[3,D,3] + x[4,D,3] + x[5,D,3] + x[6,D,3] + x[7,D,3] + x[8,D,3] + x[9,D,3] : 2.0 : True
('N', 1) : 1.0 : x[0,N,1] + x[1,N,1] + x[2,N,1] + x[3,N,1] + x[4,N,1] + x[5,N,1] + x[6,N,1] + x[7,N,1] + x[8,N,1] + x[9,N,1] : 1.0 : True
('N', 2) : 1.0 : x[0,N,2] + x[1,N,2] + x[2,N,2] + x[3,N,2] + x[4,N,2] + x[5,N,2] + x[6,N,2] + x[7,N,2] + x[8,N,2] + x[9,N,2] : 1.0 : True
('N', 3) : 3.0 : x[0,N,3] + x[1,N,3] + x[2,N,3] + x[3,N,3] + x[4,N,3] + x[5,N,3] + x[6,N,3] + x[7,N,3] + x[8,N,3] + x[9,N,3] : 3.0 : True
11 Declarations: N S D N_S_D_domain_index_0 N_S_D_domain N_S_D x C1_index C1 C2_index C2