特定范围的 Pyomo 约束

Question

以下是我尝试运行的优化代码的一部分。

from pyomo.environ import *
model = ConcreteModel()
## Define sets 
model.k = Set(initialize=['Diesel','Diesel_hybrid', 'Battery_electric'], doc='Vehicle Type')
model.i = Set(initialize=[0,1,2,3,4,5], doc='Age')
model.t = Set(initialize=[2018,2019,2020,2021,2022,2023], doc='Years')
## Define variables 
model.P = Var(model.k, model.t, bounds=(0,None), doc='number of k type vehicle purchased in year t')
model.A = Var(model.k, model.i, model.t, bounds=(0,None), doc='number of k type i year old bus in use at the end of year t')
model.R = Var(model.k, model.i, model.t, bounds=(0,20), doc='number of k type i year old bus salvaged at year t')

我正在尝试编写一个约束，该约束说，对于公共汽车 i<=4 的年龄，挽救的公共汽车数量 R[k，i，t] = 0 我尝试了以下方法。它似乎不起作用。

def constraint_5(model,k,t):
if (i<=4):
return model.R[k,i,t] == 0

我也尝试定义一个子集。那也行不通。

model.sal = Set(initialize=[0,1,2,3,4], doc='Minimum age in usage')
def constraint_5(model,k,t):
for i in model.w:
return model.R[k,i,t] == 0

谁能帮我？谢谢

Answer 1

为此，您可以为所有集合的约束编制索引，并使用Constraint.Skip跳过为不需要的索引添加约束

def constraint_5(model,k,i,t):
if i<=4:
return model.R[k,i,t] == 0
return Constraint.Skip
model.con5 = Constraint(model.k,model.i,model.t,rule=constraint_5)

或者，您可以在创建的子集上为约束编制索引

def constraint_5(model,k,i,t):
return model.R[k,i,t] == 0
model.con5 = Constraint(model.k,model.sal,model.t,rule=constraint_5)