Cbc 2.2 reports model integer-infeasible, actually feasible
|Reported by:||nowozin||Owned by:||somebody|
Cbc 2.2 reports the attached model (submitted to the lp-solve mailing list for examination) as integer feasible:
Coin Cbc and Clp Solver version 2.20.00, build Sep 20 2008 command line - /opt/coin-cbc-2.2.0/bin/cbc out.mps At line 8 NAME At line 9 ROWS At line 2700 COLUMNS At line 137775 RHS At line 138113 BOUNDS At line 141138 ENDATA Problem no_name has 2689 rows, 4032 columns and 268128 elements Coin0008I no_name read with 0 errors Continuous objective value is 145980 - 0.15 seconds Perturbing problem by 0.001 % of 478.647 - largest nonzero change 0.00146329 (% 0.000305713) - largest zero change 0.000244159 0 Obj 145980 Primal inf 3349.78 (576) Primal infeasible - objective value 153640 Cgl0000I Cut generators found to be infeasible! Pre-processing says infeasible or unbounded Total time 0.73
I personally verified Cplex 9.1 also reports the model infeasible, whereas people report later versions of Cplex, Xpress MP and SCIP producing integer-feasible solutions.