How to fix variables of the presolved model
Awaiting user input
How to fix some variables of model m after m is presolved, and obtain a solution of the corresponding sub-MIP.
I tried to fix some variables of model p = m.presolve() and solve it, however, p may introduces new variables and the mapping u: p →m is unaccessible so i can't obtain a solution of m.
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Gurobi Staff
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We do not recommend modifying the presolved model (since, as you noticed yourself, you cannot access the mapping back to the original model).
Why can't you fix the variables in the original model?
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Because I need to try many kinds of fixations and solve the sub-MIP, but i wish to presolve the original model m only once (to save time). In fact i don't need the mapping itself, i just need the solution of m, is there any method to achieve this?
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This is not possible. You should fix the variables in the original model.
How long does presolve take in your models?
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