If Constraint
AnsweredHello,
i have a binary variables W[i,c,j,t], and i want to expres this constraint:
If for a given j and a given t W[i,c,j,t]=1 so all other W for the same j and t most be equal to 0.
For example if W[2,0,0,2]=1 so for i in I for c in C, W[i,c,0,2]=0.
Thank you
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is it correct to express it like this :
model.addConstrs( (W[i,c,k,t] ==1) >> (gp.quicksum( W[j,d,k,t] for j in range(I) for d in range(C) if j != i if d !=c) == 0 ) for i in range(I) for k in range(K) for t in range(T)for c in range(C))
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Hi Rayan,
The constraint looks correct. However, you don't necessarily need an indicator constraint for that.
If your \(\texttt{W}\) are binary then the constraints
\[\begin{align*}
\sum_{i \in I, c \in C} W_{i,c,k,t} = 1 \quad \forall k \in K, t \in T
\end{align*}\]already make sure that exactly one \(W_{i,c,k,t}\) is \(1\) over all \(i,c\) for a fixed \(k,t\).
Best regards,
Jaromił0 -
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Hello Jaromi,
than you for your response,
i wrote the constraint like this :
for k in range(K):
for t in range(t):
model.addConstr(gp.quicksum(W[i,c,k,t] for i in range(I) for c in range(C))<=1)
and i found W[1,1,0,2] AND W[1,0,0,2] equal to 1.
i don't where is my error
Thank you0 -
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I would guess that
for t in range(t):is a typo and should read
for t in range(T):0 -
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Thnak you !!
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