Hi Xypron, > when starting glpsol for the model file below with > glpsol -m test.mod --tmlim 100 > the solver does not terminate within the required time.
> A lot of lines like the following are output: > | 19400: obj = 6.400000000e+001 infeas = 7.062e-014 (2) > | 19600: obj = 6.400000000e+001 infeas = 1.024e-014 (2) > | 19800: obj = 6.400000000e+001 infeas = 5.663e-014 (2) Thank you for your bug report. The solver does not stop, because the time limit is checked at the beginning of the branch-and-bound loop, however, the dual simplex is cycling and does not return. BTW, your instance is pathological (currently I am trying to analyze it). Though it is well scaled, in optimal solution to lp relaxation some constraints have huge reduced costs that explains why the dual simplex cannot terminate: 131 move[2,1,1] B 0 0 132 move[2,1,2] NU 0 0 < eps 133 move[2,1,3] NU 0 0 1.28218e+20 134 move[2,1,4] NU 0 0 < eps 135 move[2,1,5] NU 0 0 1.42691e+20 136 move[2,1,6] NU 0 0 < eps 137 move[2,1,7] NU 0 0 9.93974e+19 138 move[2,1,8] NU 0 0 < eps 139 move[2,2,1] B 0 0 140 move[2,2,2] NU 0 0 1.42098e+20 141 move[2,2,3] B -0.317426 0 142 move[2,2,4] NU 0 0 2.09366e+20 143 move[2,2,5] NU 0 0 < eps 144 move[2,2,6] NU 0 0 1.90904e+20 145 move[2,2,7] NU 0 0 < eps 146 move[2,2,8] NU 0 0 9.94232e+19 147 move[2,3,1] NU 0 0 1.28218e+20 148 move[2,3,2] B -0.682574 0 149 move[2,3,3] NU 0 0 2.55832e+20 150 move[2,3,4] NU 0 0 < eps Andrew Makhorin _______________________________________________ Bug-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-glpk
