Initializing the auxiliary gurobi variables

回答済み

Ramesh singh

2023年02月28日 11:23

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Hi, 

     i am using t3[j,i] as auxiliary variable, i need to initialize it with zero. This variable t3 is updated using constraints when optimized variable C  is set. I am sharing here partial code where CR and data are the input (python variable). Please help me whether this is the correct way or not thank you.  

t3=m.addVars(range(1,R+1),range(1,P+1),vtype=GRB.CONTINUOUS,name="t3")

C=m.addVars(range(1,P+1),range(1,M+1),lb=0,ub=1,vtype=GRB.BINARY, name="C")

for j in range(1,R+1):
    for i in range(1,P+1):
        t3[j,i].START=0

for i in range(1,P+1):
    for k in range(1,M+1):
        m.addConstr((C[i,k]==1) >> (t3[CR[k],i]==data[i]))

関連

• MIPStart

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  Matthias Miltenberger

  • Gurobi Staff

  2023年02月28日 12:55

  Hi Ramesh,

  You don't have to initialize variables. Gurobi will anyway try the zero solution and check whether this is feasible. The START attribute really makes sense when you have a valid (non-zero) starting solution available - even if it may only contain a subset of the variables. Then Gurobi will try to complete this solution and use it to have an initial primal bound to speed up the solving process.

  Please check out this guide on MIP Starts: How do I use MIP starts? – Gurobi Help Center

  I hope that helps.

  Cheers,
  Matthias

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