具有各种索引的总和内的 Pyomo sum [英] Pyomo sum inside sum with various index

问题描述

我想这样做:

但我不知道具体如何，这是我尝试过的:

but I don't know exacly how, this is what I've tried:

def R2(model, da, gr, cu):
    return sum(sum(model.Dap[asi, pe] for asi in model.A[asi, gr, cu]) for pe in model.Pd[pe, da]) <= 1
model.R2 = Constraint(model.DA, model.GR, model.CU, rule=R2)

推荐答案

我不是 100% 理解你的数学公式.

I am not 100% I understand your mathematical formulation.

根据您编写约束的方式，您似乎有多个索引集(即，它们本身在其他集上建立索引)，这通常是公式有点笨拙的症状，尽管有时是必要的.

Based on the way you write the constraint, it seems you have multiple Indexed Sets (i.e. sets which are themselves indexed over other sets), which is often a symptom that the formulation is a bit clunky, although it is sometimes necessary.

如果你想表达的是一个约束系统，即DA、GR、CU的每个元素一个约束，并且集合 Pd 和 A 在 DA、GR、CU 上被索引:

If what you are trying to express is a system of constraints, i.e. one constraint for each element of DA, GR, CU, and the sets Pd and A are indexed over DA, GR, CU:

那你应该写

def R2(model, d, g, c):
    return sum(sum(model.Dap[p] for a in model.A[g, c]) 
               for p in model.Pd[d]) <= 1

model.R2 = Constraint(model.DA, model.GR, model.CU, rule=R2)

否则，您应该尝试使表述更清晰.

Otherwise, you should try to make the formulation more clear.

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