Constraint expression

Answered

Rayan SAAD

• July 18, 2023 18:39

Helloo,

I have a probleme and i would like some help,

i want to establish different constraint for my variable S[i,c,j,t] depending on j,

So i defined different J like this :

J1=range(6,11)
J21=range(0,1)
J22=range(2,3)
J2=chain(J21,J22)
J31=range(1,2)
J32=range(3,5)
J3=chain(J31,J32)
J4=range(5,6)

After that i defined my constraint this way : 

for i in range(I):
    for c in range(C):
      for t in range(T):
        for j in J2:
           model.addConstr(S[i,c,j,t]<=15)
for i in range(I):
    for c in range(C):
      for t in range(T):
        for j in  J3:
           model.addConstr(S[i,c,j,t]<=6)

Same thing for J4 and J1...

The probleme is that i found a solution where S[2,0,3,0]=15,   while j=3 is in J3 and  my variable S shoulde be <=6.

Thank you !

0

• 

  Riley Clement

  Gurobi Staff

  • July 19, 2023 00:08

  Hi Rayan,

  As a way of debugging I suggest you add a print statement in your code:

  for i in range(I):
      for c in range(C):
        for t in range(T):
          for j in  J3:
             print(i,c,j,t)
             model.addConstr(S[i,c,j,t]<=6)

  which will make it clear if you are actually generating this constraint for S[2,0,3,0].

  The most likely explanation is that you are not.

  - Riley

  0

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