COUENNE

The COIN Couenne solver (COUENNE, Convex Over and Under ENvelopes for Nonlinear Estimation) is a spatial branch & bound algorithm that implements linearization, bound reduction, and branching techniques for Mixed-integer, Nonlinear Programming (MINLP) problems. The purpose of Couenne is to find global optima of nonconvex MINLPs.

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How to use it

ampl: option solver couenne; # change the solver
ampl: option couenne_options 'option1=value1 option2=value2'; # specify options
ampl: solve; # solve the problem

Resources

Solver options

Full list of solver options:

More details on solver options: Features guide.

Retrieving solutions

The outcome of the last optimization is stored in the AMPL parameter solve_result_num and the relative message in solve_result.

display solve_result_num, solve_result;

COUENNE solve result codes:

          0- 99 solved: optimal for an optimization problem, feasible for a satisfaction problem
        100-199 solved? solution candidate returned but error likely
        200-299 infeasible
        300-399 unbounded
        400-499 limit
        500-999 failure, no solution returned