# Questions tagged [optimality-gap]

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### Integrality gap vs Gurobi Gap

I was wondering what the difference is between the integrality gap (i.e. best known solution in relation to the LP relaxation) and the gap from the MIP solver from Gurobi, for example. As I understand ...
• 21
1 vote
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### How to achieve recording the change of objective or primal gap in solving MILP by SCIP?

I am a solver beginner, would like to ask you how to call the solver to achieve second-level recording, as documented in many articles, as shown below.
• 11
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### Calculating optimality gap when denominator goes to zero

Using an optimality gap formula that calculates an average over large sets of instances is a common practice to assess the efficiency of an algorithm. The widely-used formula employed by CPLEX is: |...
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### What exactly is the optimality-gap or what does it say in integer linear programming?

I am working since a few months with gurobi and did figure out, that the gap says how far a feasible solutions is away from the optimal solution. However, what does say it exactly? The gurobi docs ...
• 147
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### LocalSolver at 100% Gap

Can somebody help me with Localsolver? I have installed the academic license and want to solve Split Delivery VRP. I'm using the same model as seen in the website here and using the same instances too ...
• 593
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### Pyomo mipgap status monitoring

Is there a way to monitor the value of the mipgap while running an optimization model Pyomo? I would like to know how far I am from the optimality gap. Here is my ...
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### Does a pre-calculated lower bound of an MILP problem help?

I have an MILP model, say $$\begin{array}{rl} \mbox{minimize} &f_1(x) + f_2(x)\\ \mbox{subject to} &x\in X \end{array}$$ which is hard to solve. And I find it simple to solve the two ...
• 1,206