Change a MILP to an LP

[erling-d-andersen]

Hi

I want to solve the

• LP relaxation of a MILP from some C++ code call in HiGHS
• using the dual simplex optimizer.

I read the MILP from a MPS file.

ChatGPT told me to use the command

void changeToContinous(Highs &highs)
{

// Assume model already loaded
HighsLp lp = highs.getLp();

// Remove integrality from all variables
for (int i = 0; i < lp.num_col_; i++) {
lp.integrality_[i] = HighsVarType::kContinuous;
}
}

but it did do the trick.

In CPLEX you can use

CPXchgprobtype(env, lp, CPXPROB_LP);

to do what I want.

Thanks for any suggestions.

[erling-d-andersen]

I should add

highs.passModel(lp);

Sorry.