How to do a specific constrain

Answered

Benjamin Daniel Ibañez Lorca

November 02, 2023 19:00

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How can i make this constrain in gurobi?

Related to

• gurobipy-pandas

0

• 

  Maliheh Aramon

  • Gurobi Staff

  November 07, 2023 22:05

  Hi, 

  I assume that you would like to build the constraint below using gurobipy-pandas:

  \[\sum_{t^{\prime} = t} ^{t+3} x_{e, t^{\prime}, s} \leq 3, ~~ \forall e \in E, t \in \{0, \cdots, |T| - 4\}, s \in S\]

  One approach that comes to my mind is to manually construct the left-hand side of the constraints for each \(e\), \(t\), \(s\) via mapping the indices of the variable series \(x\) to a function. See the script below as an example:

  import gurobipy as gp
  from gurobipy import GRB
  import gurobipy_pandas as gppd
  import pandas as pd
  import numpy as np
  
  E = range(5)
  S = range(10)
  T = range(6)
  
  model = gp.Model()
  x = gppd.add_vars(
      model, pd.MultiIndex.from_product((E, T, S), names=("e", "t", "s")), name="x"
  )
  
  # Manually construct the LHS for each index e, t, s using the dataframe x_df
  x_df = x.reset_index()
  
  def get_lhs(index):
      e, t, s = index
      if t <= len(T) -4:
         return x_df.query("e == @e and s == @s and t >= @t and t <= @t+3")["x"].sum()
      return np.nan
  
  # Drop the nan from LHS
  LHS = x.index.map(get_lhs).dropna()
  gppd.add_constrs(
      model,
      LHS,
      GRB.LESS_EQUAL,
      3,
      name="c",
  )

  Best regards,

  Maliheh

  0

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