solver:fixed_lp_of_a_mip_is_infeasible

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solver:fixed_lp_of_a_mip_is_infeasible [2007/07/31 11:01] 127.0.0.1 external edit |
solver:fixed_lp_of_a_mip_is_infeasible [2014/10/13 11:38] tlastusilta |
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happens tells you that the model has numerical problems. We return the solution so that it can be analyzed. Most likely you'll see is that there are small infeasibilities but otherwise the solution will look pretty good. | happens tells you that the model has numerical problems. We return the solution so that it can be analyzed. Most likely you'll see is that there are small infeasibilities but otherwise the solution will look pretty good. | ||

- | You can often make this go away by turning on a more aggressive scaling (preferred, Cplex option: ''scaind 1'') or by specifying a smaller integrality tolerance (Cplex option ''epint''). You could also work on figuring out why the model is numerically difficult. If you are only interested in the primal solution of your model, the Cplex option ''solvefinal 0'' will turn of the solution of the final LP. In that case no duals will be reported. | + | You can often make this go away by turning on a more aggressive scaling (preferred, Cplex option: ''scaind 1'') or by specifying a smaller integrality tolerance (Cplex option ''epint''). You could also work on figuring out why the model is numerically difficult, as well as, try if Cplex option ''numericalemphasis'' makes a difference. If you are only interested in the primal solution of your model, the Cplex option ''solvefinal 0'' will turn of the solution of the final LP. In that case no duals will be reported. |

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solver/fixed_lp_of_a_mip_is_infeasible.txt ยท Last modified: 2014/10/13 11:38 by tlastusilta