How to terminate mpec sooner Topic is solved

Problems with syntax of GAMS
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T_k
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How to terminate mpec sooner

Post by T_k »

I am using mpec=nlpec to solve a mpec problem. however, the solver keeps running for a long time. i want to terminate early. How do I terminate after say a gap of 0.03 and still get the full feasible solution?
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dirkse
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Re: How to terminate mpec sooner

Post by dirkse »

T_k,

If you are solving your MPEC model with the NLPEC solver, than you are ultimately running a DNLP solver on a reformulated version of the problem. So the answer depends entirely on what DNLP solver you are using. Please specify.

Many DNLP solvers are local solvers, i.e. they are looking for a point that satisfies local optimality conditions (e.g. the reduced gradient is zero or nearly zero). For these, there is no concept of a well defined optimality gap. But a global solver will have such a concept. Set the optimality gap in the usual ways: most convenient is to set the GAMS parameter OPTCR.

-Steve
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