Hi, can this ALNS be used for binary variables? about alns HOT 6 CLOSED

@TNQINGYUN hi, thanks for opening an issue.

I have a repository here that uses this package to solve a problem with purely binary decisions, so yes, you can use this package for such problems. In general, you can use this package for (at least) all problems that can be expressed as (integer) linear programs.

It is up to you how to model the decisions. That will depend on the problem you're solving, and on what you need in the operators. I don't know if I can give you any further advice without knowing a little more about your problem.

So: which problem are you solving?

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Thanks for your quick reply. BTW, the link in your reply for the binary package did not work. Can you replace by a new one?

I want to solve a facility location problem with K locations and use binary variable as the decision variable. The decision variable is given as K binary variables, which can be given as the input to evaluate objective function. I want to find a fast searching heuristic and try ALNS.

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My apologies, I meant this link: https://github.com/N-Wouda/PL-Heuristic.

You might want to store the decisions for all K locations in, say, an array on the State object. Something like this, perhaps:

from alns import State
import numpy as np
from .cost_function import F

class Solution(State):
  locs: np.array

  def objective(self) -> float:
    return F(self.locs)

Where I assume you have a file cost_function.py that contains the function F(x).

from alns.

Thanks. This is very helpful. I will have a try.

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@TNQINGYUN very good, let me know if you have any further questions!

from alns.

@TNQINGYUN I'm closing this issue because I have not heard from you for some time. If you something new to discuss, feel free to let me know by opening a new issue. Have a great day!

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