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Why do various MIP solvers give differing answers to my problem ?

The MIP solver xxx gives an answer different to MIP solver yyy for my problem. Why does this happen ?

The default value of the relative optimality tolerance (optcr)is 0.1. This means that, unless otherwise specified, the solver will stop when it finds a feasible integer solution within 10% of the global optimum. Various solvers can find different solutions that fall in this 10% gap. The user can override this and force the solver to find the global optimum by setting the optcr option to 0.0 using the statement,

  option optcr = 0.0 ;

before the solve statement.

solver/why_do_various_mip_solvers_give_differing_answers_to_my_problem.txt · Last modified: 2007/07/31 14:17 (external edit)