Tobias Achterberg

I think that you have just hit a small quirk in our callback behavior at the root node. Namely, the solution *is* accepted, but at the time the next log line directly after the callback invocation ...

Hi Andreas and Jan, my guess is that you are talking about storing the solving state of a MIP solve to a file, i.e., the full search tree plus all the additional information like cuts and pseudo co...

What if instead of adding the OBJ <= CORRECT BOUND constraint you fix all the variables to their optimal solution values, add the n constraint that invalidated this solution and then calculate an I...

With the "SetSolution()" call you are modifying the user solution that is stored in the callback object. So, you can, for example, call SetSolution() for each variable individually to specify all v...

Unfortunately, this is not how gurobipy and Gurobi work. The Python API in gurobipy is, by design, just a layer around the C API of Gurobi. And the C API does not understand the concept of matrix v...

I finally found the cause of the issue. It actually has nothing to do with the MIP scenario analysis feature. It is a bug in handling SOS constraints with continuous variables inside the symmetry d...

No. Dual solutions (including shadow prices) are only defined for continuous models. They don't make any sense for integer models. If you are interested in sensitivity analysis for integer models, ...

Gurobi accepts all SOC in standard form. But when it comes to rotated or affine SOCs, it may not be able to detect the structure. Then, it falls back to the regular Q constraint mechanism, which re...

A constraint x1 + ... + xn <= 1 with xj being binary variables says that at most one them can be non-zero. This is equivalent to forming the SOS1 constraint SOS1(x1,...,xn). But the SOS1 constraint...

Sorry, this I don't know. You would need to ask in the PULP forums. I don't know the syntax of PULP or PyCharm.