Maliheh Aramon

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3. Running Gurobi model in python function

Hi Shaan,  1. Would keeping model.reset(1) instead of model.dispose() lead to an incorrect solution?  Not necessarily. The model.reset(1) essentially does not have any impact because you have alr...

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• Maliheh Aramon
• April 08, 2022 19:18
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3. Running Gurobi model in python function

Hi Aryaman, In every function call, you are not changing Gurobi parameters, you are changing the problem input that results in a new model object. You can remove the model.reset(1) from the end and...

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• Maliheh Aramon
• April 08, 2022 01:26
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3. What methods does Gurobi use to find the optimal solution of the vehicle routing problem?

Hi Vuttimate,  The parameter Method indicates the algorithm used to solve the initial root relaxation of your MIP model. According to the documentation, the default automatic setting (value of -1) ...

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• Maliheh Aramon
• April 07, 2022 02:44
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3. Writing a complex constraint with multiple for and if conditions

Hi Priyanka,  Do you want to implement the constraint below? \[\mbox{if} ~~ \sum_{l} a_{k, l, T_j} \geq 1 \rightarrow \sum_{l, m} q_{l,k,m,T_i} \leq c_k \sum_{l} a_{k, l, T_j}, ~~ \forall k, j, i ~...

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• Maliheh Aramon
• April 07, 2022 02:22
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3. Can I build a model using at the same time a matrix approach and a dictionary approach?

Hi Juan,  Which Gurobi version you are using? In Gurobi versions <= 9.5.0, it is not possible to add an instance of LinExpr(your \(\texttt{term2}\) objective) to an instance of MLinExpr (your \(\te...

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• Maliheh Aramon
• April 07, 2022 01:25
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3. model give different results after adding constraint to a non-used variable

Hi Danning,  My point was that if a decision variable does not appear in the objective function, it does not mean that the decision variable does not play a role in defining the feasible solution s...

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• Maliheh Aramon
• April 02, 2022 03:00
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3. model give different results after adding constraint to a non-used variable

Hi Danning,  The feasible space for an optimization model is defined by all its constraints, regardless of whether their associated decision variables directly appear in the objective function or n...

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• Maliheh Aramon
• March 31, 2022 18:21
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3. Set the Priority of Variables

Hi Masoud,  Yes, you can use the integer-valued BranchPriority variable attribute to set a branching priority for each variable. For example, in Gurobi C++ API, you can use the GRBVar::set(GRB_IntA...

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• Maliheh Aramon
• March 31, 2022 03:01
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3. column name in bound section not defined

Yes the warnings are strange if the model is written as an MPS file by Gurobi. Could you please post a minimal, reproducible example? Which Gurobi version are you using?  Alternatively, you can sha...

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• Maliheh Aramon
• March 31, 2022 02:32
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3. Status of Solution

Hi Masoud,  In Gurobi C++ API, you can use: if (model.get(GRB_IntAttr_Status) == GRB_OPTIMAL) Best regards, Maliheh

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• Maliheh Aramon
• March 30, 2022 02:59
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