Pyomo：一组一组

Question

I'm new to Pyomo and Python. I was wondering if someone could help me with the case of a Set Q that is based on a Set P.

model.P = pyo.Set(initialize=list(df.iloc[:,0]))
model.Q = pyo.Set(model.P)

Model.P stands for the products I read in out of a file. Model.Q is the number of possible quantities for every product. So, for example: product "AAA" has 3 different quantities, than I would like to set model.Q["AAA"] equal to the range(1,3). Product "BBB" has 7 different quantities, than I would like to set model.Q["BBB"] equal to the range(1,7).

The number of quantities are read into a list [3, 7, ...]

When I want to initialize a parameter like the following, it gives an error like below the example.

# Setup time
model.st = pyo.Param(model.P,model.Q,initialize=setupTimes,domain=pyo.NonNegativeReals)

TypeError: Cannot apply a Set operator to an indexed Set component (Q)

How can I implement this? Thanks for the help.

Answer 1

I really do not know what you intend to do with that set, but I feel there may be other ways to efficiently model your problem with just a set and a parameter of quantities for each set.

However, to do what you want, one way I suggest is to create a second set "model.PP" which has the range(max(list)) as elements. Then you create a list of tuples mapping each of model.P to the elements of model.PP appropriately which you then use to initilise model.Q ie.

model.Q = pyo.Set(within=model.P*model.PP, initialise=[("AAA",1), ("AAA",2). . .])

You can create that new list with a for loop.