python - For 循环迭代 - Pyomo 表达式中的语法错误

Question

我正在尝试在 pyomo 表达式中执行 for 循环

这是我的初始化:

N = range(len(df))
model.N             = Param(N, mutable=False)
model.r             = Var(initialize=1.0 , within=NonNegativeReals)
model.alpha         = Var(initialize=1.0 , within=NonNegativeReals)
model.a             = Var(initialize=1.0 , within=NonNegativeReals)
model.b             = Var(initialize=1.0 , within=NonNegativeReals)
model.rCon          = Constraint(expr= model.r >= 0.000001)
model.alphaCon      = Constraint(expr= model.alpha >= 0.000001)
model.aCon          = Constraint(expr= model.a >= 0.000001)
model.bCon          = Constraint(expr= model.b >= 0.000001)

当我尝试定义这样的表达式时:

model.v1 = Expression(expr= model.r + df['Xi'][0])

它编译得很好，但是当我尝试像这样进行 For 循环迭代时:

model.v2 = Expression(expr= model.r + df['Xi'][i] for i in N)

我收到这样的错误:

非常感谢您的帮助

Answer 1

看起来您正在尝试通过参数 expr 将生成器传递给表达式构造函数。在这种情况下，您需要额外的括号，如下所示:

model.v2 = 表达式(expr=(model.r + df['Xi'][i] for i in N))