Very long execution time for adding constraints

Answered

hamza addi

• November 27, 2021 18:15
• Edited

Hello, 

I hope everyone is doing fine,

I'm trying to add some constraints but it takes so much time

over 2 hours and half

list1=['x1'+str(i)for i in range(100)]
list2=['x2'+str(i)for i in range(100)]
list3=['x3'+str(i)for i in range(100)]
list4=['x4'+str(i)for i in range(100)]
list5=['x5'+str(i) for i in range(10)]
list6=['x6'+str(i) for i in range(100)]
list7=['x7'+str(i)for i in range(10)]
from tqdm import tqdm
for x1 in tqdm(list1):
     for x2 in list2:
          for x3 in list3:
                Constr=sum(var11[x1,x2,x3,x4] for x4 in list4) + sum(var12[x1,x2,x3,x4] for x4 in list5) - sum(Matrice.iloc[x1][x2]*var13[x1,x2,x4] for x4 in list6) - sum(Matrice.iloc[x1][x2]*var14[x1,x4,x5] for x4 in list6 for x5 in list7)
                model.addConstr(Constr==0)
                Constr=sum(var21[x1,x2,x3,x4] for x4 in list4) + sum(var22[x1,x2,x3,x4] for x4 in list5) - sum(Matrice.iloc[x1][x2]*var23[x1,x2,x4] for x4 in list6) - sum(Matrice.iloc[x1][x2]*var24[x1,x4,x5] for x4 in list6 for x5 in list7)
                model.addConstr(Constr==0)

I tried using sum(var11[x1,x2,x3,'*']) but i get a key error

KeyError: ('*', 'x1', 'X2', 'X4')

0

• 

  Gwyneth Butera

  Gurobi Staff

  • November 28, 2021 19:59

  There are many useful suggestions on how to improve the time to build your model in our Knowledge Base article How do I improve the time to build my model?

  In particular, I see that you repeat the same query on the data frame many times:

  Matrice.iloc[x1][x2]

  I think you can probably save a lot of time by storing that value in a variable just before the inner loop:

  for x3 in list3:

  You can probably find other ways to improve the time spent iterating in the various loops.

  G.

  0
• 

  hamza addi

  • November 29, 2021 06:15

  

  

  

  Hello,

  thank you very much for you response,i tried the trick you mentionned above and the execution time dropped from

  2 hours and a half

  to

  1 hour.

  I'm trying to explore other options.

   

  Best regards,

  Hamza

  0

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