[SCIP] Obtaining Bound Constraints from variables

[André Mazal Krauss]

Hello SCIP team,

I'm currently working on a VRP-related application, using SCIP.  I'm using
a Set Partioning formulation with Branch & Price, and my formulation is a
minimization problem.  I've started having issues with pricing of repeated
variables and slow convergence. I suspect this is happening because I'm not
correctly considering the duals of bound constraints on my pricing.

My variables are all binary, so they should have implicit linear x > 0 and
x < 1 constraints, right? How can I collect these constraints, either
during variable creation or later, so I can query their duals using
SCIPgetDualsolLinear? I don't believe this will actually help solve the
underlying issue, and I might have some reformulation to do, but having
this would help me diagnose the problem better and make sure I understand
it correctly.

I have of course read the documentation but haven't found anything on bound
constraints. Also, functions like SCIPgetNConss(scip) do not seem to
account for these. I'd like to avoid creating them explicitly over the
binary variables since this seems redundant and I'm not sure about how the
solver would behave in this situation.

Thanks in advance for your help,
André Mazal Krauss
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