Wrong solutions by Gurobi-solver
opt1234
Interface and the following parameters:
- GRB.IntParam.Method = 4
- GRB.DoubleParam.TimeLimit = 7200
- GRB.DoubleParam.MIPGap = 0.000000001
- GRB.DoubleParam.FeasibilityTol = 0.000000001
Running the same instance multiple times with the same parameters I
obtained different solutions for a minimization problem:
My main concern is an occurence of an reported optimal solution (by
Gurobi-solver) with solution value (z=454182), which shouldn't be an
optimal solution.
Another run of the same instance delivered an even worse "optimal
solution value" (z=526878).
In further runs, no optimal solutions were found, but heuristic
solutions with smaller (and hence 'better than optimal') solution
value were found.
Running the same program with the interactive shell I haven't observed
the described problem.
Here are some parts of the different outputs:
_____________________________________________________________________
Optimize a model with 70980 rows, 74564 columns and 162234 nonzeros
Presolve removed 63333 rows and 69865 columns
Presolve time: 1.64s
Presolved: 7647 rows, 4699 columns, 19879 nonzeros
Variable types: 0 continuous, 4699 integer (2414 binary)
Optimize a model with 7647 rows, 4699 columns and 19879 nonzeros
Deterministic concurrent optimizer: dual simplex and barrier
Showing barrier log only...
Presolve removed 2766 rows and 26 columns
Presolved: 4881 rows, 7422 columns, 16893 nonzeros
Root barrier log...
Ordering time: 0.11s
Barrier statistics:
Dense cols : 12
AA' NZ : 2.051e+04
Factor NZ : 2.202e+05 (roughly 7 MBytes of memory)
Factor Ops : 2.717e+07 (less than 1 second per iteration)
Threads : 1
Objective Residual
Iter Primal Dual Primal Dual Compl
Time
0 -4.04463939e+07 1.26970813e+08 2.36e+07 2.93e+03 3.02e+06
0s
1 2.10575313e+07 -1.22017448e+08 1.30e+06 2.61e+02 2.01e+05
0s
2 -1.62778890e+07 -8.95299429e+07 1.96e+05 1.40e+01 2.67e+04
1s
3 -3.47154532e+07 -5.39830742e+07 4.96e+04 1.30e+00 6.24e+03
1s
4 -4.11616654e+07 -4.68814555e+07 7.98e+03 1.33e-01 1.14e+03
1s
5 -4.15963879e+07 -4.44529945e+07 3.32e+03 4.57e-02 4.82e+02
1s
6 -4.14965922e+07 -4.27152345e+07 1.80e+03 8.19e-03 2.19e+02
1s
7 -4.14551100e+07 -4.20904656e+07 7.97e+02 2.92e-03 9.92e+01
1s
8 -4.14473036e+07 -4.17439346e+07 3.18e+02 1.11e-03 4.08e+01
1s
9 -4.14381186e+07 -4.15373499e+07 1.20e+02 3.10e-04 1.35e+01
1s
10 -4.14376851e+07 -4.15163766e+07 1.08e+02 2.45e-04 1.13e+01
1s
11 -4.14373722e+07 -4.15007468e+07 9.65e+01 2.04e-04 9.66e+00
1s
12 -4.14372302e+07 -4.14797399e+07 9.21e+01 1.85e-04 8.96e+00
1s
13 -4.14371024e+07 -4.14779208e+07 9.16e+01 1.81e-04 8.83e+00
1s
14 -4.14369419e+07 -4.14606111e+07 8.95e+01 1.76e-04 8.60e+00
1s
15 -4.14363253e+07 -4.14365968e+07 8.75e+01 1.74e-04 8.42e+00
1s
16 -4.14339795e+07 -4.14476458e+07 8.43e+01 1.61e-04 8.02e+00
1s
17 -4.14294660e+07 -4.14332412e+07 7.84e+01 1.31e-04 7.13e+00
1s
18 -4.14281963e+07 -4.14240643e+07 7.67e+01 1.30e-04 7.02e+00
1s
19 -4.14173564e+07 -4.14049493e+07 6.49e+01 1.19e-04 6.14e+00
1s
20 -4.14133393e+07 -4.13886176e+07 6.07e+01 9.30e-05 5.37e+00
1s
21 -4.14121012e+07 -4.13640519e+07 5.94e+01 8.97e-05 5.21e+00
1s
22 -4.14115959e+07 -4.13379016e+07 5.90e+01 8.94e-05 5.18e+00
1s
23 -4.14108196e+07 -4.09570370e+07 5.86e+01 8.00e-05 4.89e+00
2s
24 -4.14032976e+07 -4.07568679e+07 5.84e+01 6.21e-05 5.33e+00
2s
25 -4.13412651e+07 -4.08472749e+07 5.34e+01 6.07e-05 5.83e+00
2s
26 -4.12973876e+07 -4.10354220e+07 4.98e+01 5.54e-05 8.27e+00
2s
27 -4.12694502e+07 -4.09196717e+07 4.76e+01 5.05e-05 7.63e+00
2s
28 -4.12550390e+07 -4.08751390e+07 4.63e+01 4.89e-05 7.30e+00
2s
29 -4.12402760e+07 -4.07876208e+07 4.51e+01 4.70e-05 7.01e+00
2s
30 -4.12333527e+07 -4.07170201e+07 4.45e+01 4.61e-05 6.86e+00
2s
31 -4.12118808e+07 -4.06615736e+07 4.36e+01 4.58e-05 7.43e+00
2s
32 -4.11560037e+07 -4.06019766e+07 4.02e+01 3.80e-05 6.32e+00
2s
33 -4.11420597e+07 -4.07416679e+07 3.94e+01 3.28e-05 7.99e+00
2s
34 -4.11347507e+07 -4.06559076e+07 3.89e+01 3.12e-05 7.45e+00
2s
35 -4.11074139e+07 -4.05043359e+07 3.72e+01 2.95e-05 6.63e+00
2s
36 -4.11052486e+07 -4.05723250e+07 3.71e+01 2.94e-05 6.63e+00
2s
37 -4.10921075e+07 -4.04537543e+07 3.64e+01 2.86e-05 6.31e+00
2s
38 -4.10822363e+07 -4.04280884e+07 3.60e+01 2.83e-05 6.27e+00
2s
39 -4.10592987e+07 -4.04498072e+07 3.50e+01 2.81e-05 6.38e+00
2s
40 -4.10110258e+07 -4.03841103e+07 3.29e+01 2.71e-05 6.28e+00
2s
Barrier performed 40 iterations in 2.29 seconds
Optimization interrupted
Concurrent spin time: 1.60s (can be avoided by choosing Method=3)
Solved with dual simplex
Solved in 4593 iterations and 2.31 seconds
Optimal objective -3.787085689e+07
Root relaxation: objective -3.787086e+07, 4593 iterations, 2.31
seconds
Nodes | Current Node | Objective Bounds |
Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/
Node Time
0 0 -3.787e+07 0 622 - -3.787e+07 -
- 6s
0 0 -3.718e+07 0 2901 - -3.718e+07 -
- 8s
0 0 -3.717e+07 0 2945 - -3.717e+07 -
- 8s
0 0 -3.717e+07 0 759 - -3.717e+07 -
- 9s
H 0 0 3257805.0000 -3.717e+07 1241% -
10s
0 2 -3.717e+07 0 759 3257805.00 -3.717e+07 1241% -
12s
107 108 -3.566e+07 53 707 3257805.00 -3.715e+07 1240% 13.1
15s
887 889 -1.457e+07 413 535 3257805.00 -3.715e+07 1240% 9.8
20s
* 1419 1391 736 1250203.0000 -3.715e+07 3072% 11.7
23s
* 1565 1541 606 1215462.0000 -3.715e+07 3157% 12.3
24s
1635 1614 -3.569e+07 29 748 1215462.00 -3.697e+07 3141% 12.5
25s
H 1778 1629 805325.00000 -3.697e+07 4690% 12.4
30s
H 1778 1547 524814.00000 -3.697e+07 7143% 12.4
30s
1782 1549 -1.721e+07 196 2805 524814.000 -3.684e+07 7119% 12.4
36s
1786 1554 -3.679e+07 11 821 524814.000 -3.679e+07 7110% 18.8
167s
1851 1596 -3.613e+07 29 675 524814.000 -3.613e+07 6985% 20.9
170s
2001 1696 -3.540e+07 65 639 524814.000 -3.540e+07 6845% 25.6
179s
2020 1710 -3.535e+07 68 641 524814.000 -3.535e+07 6836% 26.8
181s
H 2030 1634 473580.00000 -3.535e+07 7565% 27.6
181s
H 2067 1589 473148.00000 -3.533e+07 7567% 28.1
182s
2153 1647 -3.527e+07 105 2811 473148.000 -3.527e+07 7555% 29.7
185s
2341 1771 -3.486e+07 158 909 473148.000 -3.525e+07 7550% 32.8
190s
H 2442 1752 466908.00000 -3.525e+07 7649% 33.5
192s
H 2496 1713 459078.00000 -3.525e+07 7778% 33.6
194s
2497 1741 -3.428e+07 202 712 459078.000 -3.525e+07 7778% 33.6
196s
H 2676 1796 456798.00000 -3.525e+07 7817% 33.1
199s
2693 1805 -3.441e+07 261 681 456798.000 -3.525e+07 7817% 33.0
200s
H 2703 1740 455526.00000 -3.525e+07 7838% 33.1
200s
H 2741 1711 454182.00000 -3.525e+07 7861% 33.7
201s
2831 1779 -3.352e+07 292 2737 454182.000 -3.525e+07 7861% 34.0
212s
2947 1859 -3.350e+07 320 2739 454182.000 -3.525e+07 7861% 33.6
215s
3091 1955 -3.222e+07 369 2737 454182.000 -3.525e+07 7861% 34.5
220s
3393 2155 -2.858e+07 433 2680 454182.000 -3.525e+07 7861% 34.8
225s
3761 2400 -2.414e+07 524 2634 454182.000 -3.525e+07 7861% 34.1
230s
4050 2593 -1.908e+07 594 2566 454182.000 -3.525e+07 7861% 34.4
235s
4471 2874 -1.256e+07 706 2500 454182.000 -3.525e+07 7861% 34.0
240s
4844 3123 -9359053.3 817 2429 454182.000 -3.525e+07 7861% 32.7
245s
5220 3427 -2810662.9 950 56 454182.000 -3.525e+07 7861% 32.6
250s
5636 3800 -3.493e+07 55 2794 454182.000 -3.518e+07 7845% 32.8
255s
5924 4088 -3.455e+07 66 2785 454182.000 -3.518e+07 7845% 32.3
260s
6215 4369 -3.348e+07 76 2773 454182.000 -3.518e+07 7845% 31.9
265s
6666 4825 -3.243e+07 130 659 454182.000 -3.518e+07 7845% 32.0
270s
6999 5181 -2.934e+07 208 2783 454182.000 -3.518e+07 7845% 32.4
275s
7288 5448 -2.903e+07 257 2758 454182.000 -3.518e+07 7845% 33.0
280s
7508 5677 -2.805e+07 330 2771 454182.000 -3.518e+07 7845% 33.7
285s
7965 6108 -2.694e+07 439 2742 454182.000 -3.518e+07 7845% 32.6
290s
8415 6457 -2.609e+07 532 2636 454182.000 -3.518e+07 7845% 31.6
295s
8937 6973 -2.424e+07 660 2543 454182.000 -3.518e+07 7845% 30.5
300s
9432 7484 -2.074e+07 769 2409 454182.000 -3.518e+07 7845% 29.6
305s
9782 7826 -6761846.1 825 2353 454182.000 -3.518e+07 7845% 29.4
429s
9784 7830 -2304970.0 825 76 454182.000 -3.518e+07 7845% 29.4
433s
9814 7841 -1541894.4 834 64 454182.000 -3.518e+07 7845% 29.4
436s
10013 8052 -3.451e+07 64 2808 454182.000 -3.509e+07 7826% 29.0
442s
10102 8127 -2.704e+07 118 639 454182.000 -3.509e+07 7826% 29.0
456s
10390 8418 -2.243e+07 267 2748 454182.000 -3.509e+07 7826% 28.6
460s
10839 8724 -1.980e+07 424 2675 454182.000 -3.509e+07 7826% 28.0
465s
10989 8872 -1.919e+07 464 2643 454182.000 -3.509e+07 7826% 27.8
470s
11357 9222 -1.806e+07 522 2591 454182.000 -3.509e+07 7826% 27.5
475s
11904 9782 -1.034e+07 567 2566 454182.000 -3.509e+07 7826% 27.1
481s
12465 10306 -8068308.5 704 2379 454182.000 -3.509e+07 7826% 26.4
485s
12949 10770 -5446763.2 762 2318 454182.000 -3.509e+07 7826% 26.0
490s
13408 11207 -4157637.1 766 27 454182.000 -3.509e+07 7826% 25.7
495s
14006 11648 -1.559e+07 195 566 454182.000 -3.508e+07 7824% 25.3
500s
14490 12141 -8632597.9 384 2585 454182.000 -3.508e+07 7824% 24.8
505s
14957 12601 -6250625.1 532 2494 454182.000 -3.508e+07 7824% 24.3
510s
15263 12896 -1701509.8 587 2390 454182.000 -3.508e+07 7824% 24.1
515s
15674 13323 -546333.60 679 38 454182.000 -3.508e+07 7824% 23.8
520s
16218 13781 -6298614.9 252 2677 454182.000 -3.507e+07 7822% 23.4
525s
16877 14433 -49159.138 639 2396 454182.000 -3.507e+07 7822% 22.9
530s
17347 14882 -8646928.0 253 2679 454182.000 -3.503e+07 7812% 22.6
535s
18002 15521 -752986.23 576 2438 454182.000 -3.503e+07 7812% 22.0
540s
18556 16057 -7728042.9 269 2673 454182.000 -3.500e+07 7805% 21.7
545s
19091 16559 -190908.64 623 2436 454182.000 -3.500e+07 7805% 21.4
550s
19342 16799 -1.805e+07 113 2763 454182.000 -3.500e+07 7805% 22.2
555s
19522 16979 -1.711e+07 140 2733 454182.000 -3.500e+07 7805% 22.7
560s
19768 17225 -1.433e+07 185 2715 454182.000 -3.500e+07 7805% 23.1
565s
19983 17441 -9904243.3 216 2705 454182.000 -3.500e+07 7805% 23.5
570s
20046 17505 -7490063.7 226 2689 454182.000 -3.500e+07 7805% 23.5
598s
20159 17616 -9177381.2 242 574 454182.000 -3.500e+07 7805% 23.5
600s
20450 17907 -8873518.6 283 2720 454182.000 -3.500e+07 7805% 23.7
605s
20821 18278 -7022537.3 349 2691 454182.000 -3.500e+07 7805% 23.8
610s
21236 18682 -5323460.0 434 2572 454182.000 -3.500e+07 7805% 23.7
615s
21650 19082 -4239696.2 498 2574 454182.000 -3.500e+07 7805% 23.7
620s
22038 19467 -2934799.8 612 2489 454182.000 -3.500e+07 7805% 23.8
625s
22263 19716 -1544440.6 679 2395 454182.000 -3.500e+07 7805% 23.8
630s
22661 20063 -1146684.0 767 44 454182.000 -3.497e+07 7800% 23.6
635s
23106 20500 -1.275e+07 190 640 454182.000 -3.497e+07 7800% 23.5
640s
23524 20874 -8624617.2 246 2711 454182.000 -3.497e+07 7800% 23.4
645s
24016 21368 -5514969.1 410 2569 454182.000 -3.497e+07 7800% 23.1
650s
24594 21899 -3789495.3 475 2561 454182.000 -3.497e+07 7800% 22.9
655s
25034 22362 -1559555.6 638 2367 454182.000 -3.497e+07 7800% 22.7
660s
25631 22844 -1049458.9 653 2365 454182.000 -3.497e+07 7800% 22.3
665s
26051 23293 -8452120.6 112 2646 454182.000 -3.495e+07 7795% 22.4
673s
26174 23420 -1642146.9 125 2514 454182.000 -3.495e+07 7795% 22.5
675s
26700 23892 -2119621.6 199 2539 454182.000 -3.494e+07 7793% 22.3
680s
27223 24379 -7875248.7 232 2684 454182.000 -3.489e+07 7782% 22.2
685s
27750 24905 -485798.58 524 2485 454182.000 -3.489e+07 7782% 22.0
690s
28465 25591 -6180310.4 284 2672 454182.000 -3.489e+07 7782% 21.7
695s
28967 26066 -2.192e+07 93 613 454182.000 -3.489e+07 7781% 21.5
700s
29369 26464 -8377710.2 235 2707 454182.000 -3.489e+07 7781% 21.5
705s
29880 26983 -4494834.9 352 2662 454182.000 -3.489e+07 7781% 21.4
710s
30393 27453 -2086516.3 504 2567 454182.000 -3.489e+07 7781% 21.3
715s
30978 28017 -2.027e+07 48 639 454182.000 -3.489e+07 7781% 21.0
720s
31462 28471 -2.649e+07 55 2804 454182.000 -3.488e+07 7780% 20.9
725s
32067 29075 -6497962.7 301 2671 454182.000 -3.488e+07 7780% 20.7
730s
32566 29565 -957579.51 601 2488 454182.000 -3.488e+07 7780% 20.6
735s
33021 29922 282662.189 78 2426 454182.000 -3.486e+07 7776% 20.6
740s
33525 30412 -6675933.5 213 2709 454182.000 -3.486e+07 7776% 20.5
745s
34134 30983 -563632.85 476 2549 454182.000 -3.486e+07 7776% 20.3
750s
34729 31565 -1.141e+07 191 2740 454182.000 -3.480e+07 7762% 20.1
755s
35286 32091 -4364307.6 380 2638 454182.000 -3.480e+07 7762% 20.0
760s
35860 32670 -510626.79 564 2493 454182.000 -3.480e+07 7762% 19.8
765s
36482 33230 -1.060e+07 202 2726 454182.000 -3.474e+07 7750% 19.7
770s
36935 33683 -4075246.7 406 2614 454182.000 -3.474e+07 7750% 19.6
775s
37563 34267 -1.691e+07 133 2728 454182.000 -3.472e+07 7745% 19.4
780s
38139 34843 -3543548.4 440 2589 454182.000 -3.472e+07 7745% 19.4
785s
38769 35397 -1.075e+07 85 2737 454182.000 -3.471e+07 7743% 19.2
790s
39391 36001 -9960608.1 159 596 454182.000 -3.470e+07 7740% 19.1
795s
39960 36530 -2675252.9 382 2544 454182.000 -3.470e+07 7740% 18.9
800s
40566 37115 -1.785e+07 175 2717 454182.000 -3.469e+07 7738% 18.8
805s
40890 37417 -2.744e+07 396 759 454182.000 -3.469e+07 7738% 18.7
858s
40892 37418 -961205.15 356 622 454182.000 -3.469e+07 7738% 18.7
862s
40893 37419 -1.385e+07 744 2900 454182.000 -3.469e+07 7738% 18.7
865s
40894 37420 -2.800e+07 160 2890 454182.000 -3.469e+07 7738% 18.7
870s
40896 37421 -2.817e+07 163 2879 454182.000 -3.469e+07 7738% 18.7
880s
40898 37422 -3169943.0 460 2893 454182.000 -3.469e+07 7738% 18.7
888s
40899 37423 -1852028.1 446 3023 454182.000 -3.469e+07 7738% 18.7
907s
40900 37424 -1280251.8 201 2892 454182.000 -3.469e+07 7738% 18.7
914s
40901 37424 -2.817e+07 163 3060 454182.000 -3.469e+07 7738% 18.7
959s
40902 37425 105235.172 61 3045 454182.000 -3.469e+07 7738% 18.7
991s
40903 37426 -1079000.5 529 2889 454182.000 -3.469e+07 7738% 18.7
997s
40904 37426 -5489220.4 297 2902 454182.000 -3.469e+07 7738% 18.7
1002s
40905 37427 -6822354.1 502 3079 454182.000 -3.469e+07 7738% 18.7
1067s
40906 37428 -1.050e+07 286 0 454182.000 -3.469e+07 7738% 18.7
1120s
Cutting planes:
Gomory: 284
Explored 40908 nodes (1065071 simplex iterations) in 1171.89 seconds
Thread count was 2 (of 2 available processors)
Optimal solution found (tolerance 1.00e-09)
Best objective 4.541820000000e+05, best bound 4.541820000000e+05, gap
0.0%
________________________________________________________________________________
Optimize a model with 70980 rows, 74564 columns and 162234 nonzeros
Presolve removed 63333 rows and 69865 columns
Presolve time: 1.53s
Presolved: 7647 rows, 4699 columns, 19879 nonzeros
Variable types: 0 continuous, 4699 integer (2414 binary)
Optimize a model with 7647 rows, 4699 columns and 19879 nonzeros
Deterministic concurrent optimizer: dual simplex and barrier
Showing barrier log only...
Presolve removed 2766 rows and 26 columns
Presolved: 4881 rows, 7422 columns, 16893 nonzeros
Root barrier log...
Ordering time: 0.11s
Barrier statistics:
Dense cols : 12
AA' NZ : 2.051e+04
Factor NZ : 2.038e+05 (roughly 7 MBytes of memory)
Factor Ops : 2.202e+07 (less than 1 second per iteration)
Threads : 1
Objective Residual
Iter Primal Dual Primal Dual Compl
Time
0 -4.04463939e+07 1.26970813e+08 2.36e+07 2.93e+03 3.02e+06
0s
1 2.10575313e+07 -1.22017448e+08 1.30e+06 2.61e+02 2.01e+05
0s
2 -1.62778890e+07 -8.95299429e+07 1.96e+05 1.40e+01 2.67e+04
0s
3 -3.47154532e+07 -5.39830742e+07 4.96e+04 1.30e+00 6.24e+03
0s
4 -4.11616654e+07 -4.68814555e+07 7.98e+03 1.33e-01 1.14e+03
0s
5 -4.15963879e+07 -4.44529945e+07 3.32e+03 4.57e-02 4.82e+02
0s
6 -4.14965923e+07 -4.27152346e+07 1.80e+03 8.19e-03 2.19e+02
1s
7 -4.14551098e+07 -4.20904656e+07 7.97e+02 2.92e-03 9.92e+01
1s
8 -4.14473037e+07 -4.17439340e+07 3.18e+02 1.11e-03 4.08e+01
1s
9 -4.14381190e+07 -4.15373496e+07 1.20e+02 3.10e-04 1.35e+01
1s
10 -4.14376856e+07 -4.15163765e+07 1.08e+02 2.45e-04 1.13e+01
1s
11 -4.14373728e+07 -4.15007467e+07 9.65e+01 2.04e-04 9.66e+00
1s
12 -4.14372308e+07 -4.14797397e+07 9.21e+01 1.85e-04 8.96e+00
1s
13 -4.14371029e+07 -4.14779208e+07 9.16e+01 1.81e-04 8.83e+00
1s
14 -4.14369422e+07 -4.14606113e+07 8.95e+01 1.76e-04 8.60e+00
1s
15 -4.14363255e+07 -4.14365968e+07 8.75e+01 1.74e-04 8.42e+00
1s
16 -4.14336839e+07 -4.14501296e+07 8.38e+01 1.67e-04 8.14e+00
1s
17 -4.14304505e+07 -4.14481294e+07 7.97e+01 1.12e-04 6.96e+00
1s
18 -4.14293401e+07 -4.14475246e+07 7.82e+01 1.10e-04 6.84e+00
1s
19 -4.14282030e+07 -4.14368630e+07 7.66e+01 1.08e-04 6.71e+00
1s
20 -4.14169348e+07 -4.14229531e+07 6.49e+01 1.01e-04 6.17e+00
1s
21 -4.14133670e+07 -4.13980493e+07 6.11e+01 8.41e-05 5.34e+00
1s
22 -4.14119118e+07 -4.13836430e+07 5.95e+01 7.87e-05 5.07e+00
1s
23 -4.14115001e+07 -4.13463194e+07 5.91e+01 7.77e-05 5.01e+00
1s
24 -4.14105939e+07 -4.13493138e+07 5.86e+01 7.58e-05 4.95e+00
1s
25 -4.14104605e+07 -4.09457243e+07 5.85e+01 7.57e-05 4.95e+00
1s
26 -4.14103001e+07 -4.11549716e+07 5.85e+01 7.57e-05 4.96e+00
1s
27 -4.14060846e+07 -4.08688270e+07 5.83e+01 5.91e-05 5.09e+00
1s
28 -4.13287648e+07 -4.09291765e+07 5.22e+01 4.18e-05 6.04e+00
1s
29 -4.12879744e+07 -4.08943398e+07 4.88e+01 3.77e-05 6.28e+00
2s
30 -4.12496472e+07 -4.07892478e+07 4.56e+01 3.29e-05 5.36e+00
2s
31 -4.12393872e+07 -4.07213648e+07 4.47e+01 3.19e-05 5.21e+00
2s
32 -4.12321457e+07 -4.06157195e+07 4.41e+01 3.12e-05 5.08e+00
2s
33 -4.12106232e+07 -4.05623863e+07 4.32e+01 3.08e-05 5.49e+00
2s
34 -4.11502433e+07 -4.07113780e+07 3.97e+01 2.81e-05 6.59e+00
2s
35 -4.11192005e+07 -4.04962270e+07 3.80e+01 2.48e-05 5.46e+00
2s
36 -4.11027407e+07 -4.04232436e+07 3.71e+01 2.43e-05 5.24e+00
2s
37 -4.11023157e+07 -4.05154973e+07 3.70e+01 2.42e-05 5.24e+00
2s
38 -4.11012318e+07 -4.04438876e+07 3.70e+01 2.42e-05 5.23e+00
2s
Barrier performed 38 iterations in 1.92 seconds
Optimization interrupted
Concurrent spin time: 1.20s (can be avoided by choosing Method=3)
Solved with dual simplex
Solved in 4622 iterations and 1.94 seconds
Optimal objective -3.787085689e+07
Root relaxation: objective -3.787086e+07, 4622 iterations, 1.94
seconds
Nodes | Current Node | Objective Bounds |
Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/
Node Time
0 0 -3.787e+07 0 616 - -3.787e+07 -
- 6s
0 0 -3.725e+07 0 2912 - -3.725e+07 -
- 8s
0 0 -3.725e+07 0 865 - -3.725e+07 -
- 8s
0 0 -3.725e+07 0 2902 - -3.725e+07 -
- 8s
0 0 -3.725e+07 0 2797 - -3.725e+07 - -
10s
H 0 0 786118.00000 -3.725e+07 4839% -
11s
0 2 -3.725e+07 0 2797 786118.000 -3.725e+07 4839% -
14s
28 30 -3.616e+07 11 2811 786118.000 -3.709e+07 4819% 80.6
15s
H 160 144 784311.00000 -3.709e+07 4829% 18.5
18s
326 327 -2.995e+07 163 575 784311.000 -3.709e+07 4829% 13.1
20s
979 980 -2.375e+07 464 170 784311.000 -3.709e+07 4829% 12.4
25s
H 1458 1342 784251.00000 -3.706e+07 4825% 13.1
29s
H 1460 1277 759882.00000 -3.706e+07 4977% 13.1
32s
H 1460 1213 599287.00000 -3.706e+07 6284% 13.1
32s
1462 1214 -1.435e+07 576 2791 599287.000 -3.706e+07 6284% 13.1
36s
1465 1216 -2.641e+07 246 2831 599287.000 -3.667e+07 6218% 13.1
41s
H 1468 1159 596225.00000 -3.667e+07 6250% 25.6
45s
1469 1160 -3.664e+07 11 792 596225.000 -3.664e+07 6245% 26.9
169s
1471 1162 -3.661e+07 12 772 596225.000 -3.661e+07 6240% 27.0
170s
H 1497 1119 585870.00000 -3.628e+07 6292% 28.2
171s
H 1554 1100 585535.00000 -3.595e+07 6240% 30.5
173s
H 1555 1049 583500.00000 -3.595e+07 6261% 30.5
173s
1586 1070 -3.589e+07 45 2838 583500.000 -3.589e+07 6251% 31.0
175s
H 1662 1071 583194.00000 -3.576e+07 6232% 34.9
178s
1700 1097 -3.567e+07 74 712 583194.000 -3.567e+07 6216% 37.5
180s
H 1740 1076 582996.00000 -3.560e+07 6207% 38.4
181s
H 1781 1061 582870.00000 -3.560e+07 6208% 39.8
182s
H 1820 1043 579990.00000 -3.560e+07 6239% 41.4
183s
1864 1072 -3.528e+07 115 760 579990.000 -3.560e+07 6239% 43.2
185s
H 1941 1065 579322.00000 -3.560e+07 6246% 45.2
187s
1995 1119 -1.988e+07 148 699 579322.000 -3.560e+07 6246% 46.1
192s
H 2056 1111 578004.00000 -3.560e+07 6260% 46.4
194s
2076 1136 -3.447e+07 159 676 578004.000 -3.560e+07 6260% 46.3
200s
H 2121 1106 559692.00000 -3.560e+07 6461% 46.2
200s
H 2172 1124 536701.00000 -3.560e+07 6734% 46.2
206s
2281 1200 -3.409e+07 212 513 536701.000 -3.560e+07 6734% 45.7
210s
2586 1402 -3.385e+07 297 515 536701.000 -3.560e+07 6734% 43.9
215s
2828 1563 -3.350e+07 357 801 536701.000 -3.560e+07 6734% 45.3
220s
2990 1671 -3.252e+07 395 497 536701.000 -3.560e+07 6734% 45.9
225s
3322 1893 -3.165e+07 454 2693 536701.000 -3.560e+07 6734% 44.9
230s
3620 2153 -3.092e+07 507 2687 536701.000 -3.560e+07 6734% 43.6
235s
4021 2554 -2.762e+07 614 2576 536701.000 -3.560e+07 6734% 42.5
240s
4243 2776 -2.077e+07 671 2546 536701.000 -3.560e+07 6734% 43.4
245s
4622 3154 -1.774e+07 814 2449 536701.000 -3.560e+07 6734% 42.5
250s
4931 3460 -9538212.4 924 78 536701.000 -3.560e+07 6734% 42.9
255s
5008 3490 -4418274.0 933 13 536701.000 -3.560e+07 6734% 44.4
262s
H 5091 3555 535946.00000 -3.556e+07 6734% 45.8
265s
H 5097 3561 535538.00000 -3.551e+07 6732% 45.9
265s
5239 3703 -3.480e+07 106 881 535538.000 -3.542e+07 6713% 48.6
270s
5454 3918 -3.315e+07 167 704 535538.000 -3.542e+07 6713% 49.7
277s
5547 4011 -3.292e+07 191 2831 535538.000 -3.542e+07 6713% 50.2
280s
5801 4265 -3.124e+07 259 2815 535538.000 -3.542e+07 6713% 50.4
285s
6067 4531 -3.061e+07 312 2837 535538.000 -3.542e+07 6713% 50.1
290s
6180 4644 -3.056e+07 341 2802 535538.000 -3.542e+07 6713% 50.0
406s
6313 4779 -2.988e+07 379 2742 535538.000 -3.542e+07 6713% 49.4
410s
6367 4829 -3.010e+07 393 2772 535538.000 -3.542e+07 6713% 49.1
417s
H 6420 4857 528762.00000 -3.542e+07 6798% 49.0
417s
6421 4887 -2.971e+07 406 2729 528762.000 -3.542e+07 6798% 49.0
420s
6841 5307 -2.903e+07 514 2680 528762.000 -3.542e+07 6798% 47.0
426s
7140 5604 -2.908e+07 591 2649 528762.000 -3.542e+07 6798% 45.8
431s
7450 5917 -2.833e+07 670 2562 528762.000 -3.542e+07 6798% 44.4
435s
7731 6195 -2.577e+07 728 2526 528762.000 -3.542e+07 6798% 44.0
441s
7948 6413 -1.938e+07 781 2507 528762.000 -3.542e+07 6798% 44.0
445s
8136 6601 -8640856.0 834 2421 528762.000 -3.542e+07 6798% 43.9
450s
8476 6858 cutoff 883 528762.000 -3.542e+07 6798% 43.2
456s
8953 7312 -2.964e+07 267 2783 528762.000 -3.542e+07 6798% 41.7
460s
9474 7833 -2.689e+07 500 2697 528762.000 -3.542e+07 6798% 40.0
465s
9907 8247 -2.400e+07 609 2594 528762.000 -3.542e+07 6798% 39.1
470s
10246 8581 -2.295e+07 664 2475 528762.000 -3.542e+07 6798% 38.3
475s
10929 9314 -1.690e+07 726 2428 528762.000 -3.542e+07 6798% 36.4
480s
11259 9454 -2965516.8 766 80 528762.000 -3.542e+07 6798% 36.4
485s
11745 10021 -1.967e+07 67 721 528762.000 -3.542e+07 6798% 35.6
490s
11820 10111 -1.858e+07 123 678 528762.000 -3.542e+07 6798% 35.5
502s
11945 10172 -1.714e+07 195 2813 528762.000 -3.542e+07 6798% 35.6
505s
12305 10527 -1.437e+07 292 2730 528762.000 -3.542e+07 6798% 35.0
510s
12804 11038 -1.090e+07 440 2583 528762.000 -3.542e+07 6798% 34.0
515s
13343 11517 -8091973.0 539 2435 528762.000 -3.542e+07 6798% 33.1
520s
13902 12073 -4056292.1 592 2364 528762.000 -3.542e+07 6798% 32.2
525s
14551 12654 -2.704e+07 61 2793 528762.000 -3.542e+07 6798% 31.3
530s
15065 13165 -9677398.5 350 2676 528762.000 -3.542e+07 6798% 30.8
535s
15613 13676 -2.348e+07 92 694 528762.000 -3.542e+07 6798% 30.0
540s
16025 14096 -8675285.4 344 2664 528762.000 -3.542e+07 6798% 29.7
545s
16410 14461 -4396226.4 590 2457 528762.000 -3.542e+07 6798% 29.2
550s
16930 14931 -5616892.3 81 532 528762.000 -3.542e+07 6798% 28.8
555s
17425 15398 -1.724e+07 145 681 528762.000 -3.542e+07 6798% 28.3
560s
18032 15992 -1797192.0 473 2495 528762.000 -3.542e+07 6798% 27.7
565s
18759 16686 -7243606.3 238 2700 528762.000 -3.541e+07 6796% 27.1
570s
H18818 16744 526878.00000 -3.541e+07 6820% 27.2
574s
18820 16746 -4703545.1 281 2697 526878.000 -3.541e+07 6820% 27.2
575s
19119 17031 -2.715e+07 82 655 526878.000 -3.535e+07 6810% 27.5
580s
19227 17138 -2.582e+07 103 665 526878.000 -3.535e+07 6810% 28.4
585s
19509 17421 -1.846e+07 181 713 526878.000 -3.535e+07 6810% 29.1
590s
19541 17451 -1.840e+07 188 697 526878.000 -3.535e+07 6810% 29.3
638s
19586 17499 -1.838e+07 194 742 526878.000 -3.535e+07 6810% 29.5
640s
19773 17685 -1.491e+07 241 2692 526878.000 -3.535e+07 6810% 30.1
645s
19957 17871 -1.423e+07 280 2675 526878.000 -3.535e+07 6810% 30.5
651s
20181 18093 -1.400e+07 326 2649 526878.000 -3.535e+07 6810% 30.6
655s
20457 18368 -1.207e+07 393 2601 526878.000 -3.535e+07 6810% 30.4
660s
20778 18690 -1.056e+07 450 2532 526878.000 -3.535e+07 6810% 30.2
665s
21036 18948 -9688772.7 522 2502 526878.000 -3.535e+07 6810% 30.2
670s
21253 19149 -8737316.0 562 2443 526878.000 -3.535e+07 6810% 30.0
675s
21624 19517 151983.355 623 2358 526878.000 -3.535e+07 6810% 29.8
680s
21931 19775 -6147858.6 168 2681 526878.000 -3.535e+07 6810% 29.5
685s
22311 20147 -2.659e+07 76 690 526878.000 -3.528e+07 6796% 29.3
690s
22947 20759 -3290957.0 373 2615 526878.000 -3.524e+07 6788% 28.7
695s
23540 21340 -2.555e+07 157 616 526878.000 -3.523e+07 6787% 28.3
700s
24244 22006 -3174643.6 468 2569 526878.000 -3.523e+07 6787% 27.7
706s
24747 22496 -2.399e+07 156 633 526878.000 -3.523e+07 6787% 27.4
710s
25319 23057 -4731261.5 353 2615 526878.000 -3.523e+07 6787% 26.9
715s
25968 23673 -1.706e+07 119 600 526878.000 -3.523e+07 6787% 26.5
720s
26471 24165 -5903655.0 312 2620 526878.000 -3.523e+07 6787% 26.2
725s
27119 24752 -2.695e+07 57 2763 526878.000 -3.523e+07 6787% 25.9
730s
27684 25297 -5205989.8 298 2637 526878.000 -3.523e+07 6787% 25.5
735s
28198 25779 -2.686e+07 64 655 526878.000 -3.523e+07 6787% 25.4
740s
28538 26144 -8459433.8 201 750 526878.000 -3.523e+07 6787% 25.3
745s
28949 26545 -3708129.7 337 2598 526878.000 -3.523e+07 6787% 25.2
750s
29583 27159 -329106.22 546 2477 526878.000 -3.523e+07 6787% 24.9
755s
30032 27569 -3460451.1 196 2600 526878.000 -3.523e+07 6787% 24.7
760s
30499 28005 -1.759e+07 133 599 526878.000 -3.523e+07 6787% 24.6
765s
30963 28462 -7719325.0 257 2699 526878.000 -3.523e+07 6787% 24.3
770s
31283 28764 -1846230.4 495 2538 526878.000 -3.523e+07 6787% 24.3
775s
31626 29073 -2.704e+07 84 681 526878.000 -3.519e+07 6779% 24.3
780s
31919 29327 -411720.50 114 2485 526878.000 -3.519e+07 6779% 24.3
785s
32504 29865 -2.568e+07 161 647 526878.000 -3.519e+07 6779% 24.1
790s
33008 30348 -4036312.8 427 2595 526878.000 -3.519e+07 6779% 23.9
795s
33611 30942 -2.040e+07 83 626 526878.000 -3.515e+07 6772% 23.6
800s
34082 31395 -6322961.3 277 2678 526878.000 -3.515e+07 6772% 23.5
805s
34771 32044 -3.496e+07 44 651 526878.000 -3.515e+07 6772% 23.1
810s
35364 32637 -6012041.1 353 2695 526878.000 -3.515e+07 6772% 23.0
815s
36043 33288 490745.307 694 2356 526878.000 -3.515e+07 6772% 22.7
820s
36552 33792 -4849168.5 287 2676 526878.000 -3.515e+07 6772% 22.6
825s
37126 34343 -2.647e+07 31 2817 526878.000 -3.515e+07 6772% 22.4
830s
37689 34889 -1.724e+07 80 2782 526878.000 -3.514e+07 6770% 22.3
835s
38062 35261 -6590311.0 209 2721 526878.000 -3.514e+07 6770% 22.2
841s
38398 35583 -2962924.3 362 2607 526878.000 -3.514e+07 6770% 22.2
845s
38911 36071 -1.734e+07 79 627 526878.000 -3.512e+07 6766% 22.1
850s
39402 36551 -6346129.5 252 2687 526878.000 -3.512e+07 6766% 22.0
855s
39929 37061 -3.185e+07 109 580 526878.000 -3.512e+07 6765% 21.9
860s
40228 37366 -8404913.9 244 2668 526878.000 -3.512e+07 6765% 22.1
865s
40619 37760 -3959448.5 383 2629 526878.000 -3.512e+07 6765% 22.0
870s
40987 38116 -2.262e+07 704 2797 526878.000 -3.512e+07 6765% 21.9
914s
40989 38117 -2.735e+07 103 616 526878.000 -3.512e+07 6765% 21.9
918s
40990 38118 -2.027e+07 73 2884 526878.000 -3.512e+07 6765% 21.9
921s
40991 38119 -8931047.2 359 2870 526878.000 -3.512e+07 6765% 21.9
927s
40992 38119 -850735.95 508 2896 526878.000 -3.512e+07 6765% 21.9
933s
40993 38120 -2.073e+07 183 2898 526878.000 -3.512e+07 6765% 21.9
939s
40994 38121 -3.205e+07 106 2893 526878.000 -3.512e+07 6765% 21.9
944s
40995 38121 -6627748.8 582 2890 526878.000 -3.512e+07 6765% 21.9
951s
40996 38122 -850735.95 508 2877 526878.000 -3.512e+07 6765% 21.9
957s
40997 38123 -1.390e+07 342 2885 526878.000 -3.512e+07 6765% 21.9
962s
40998 38123 -5462710.2 299 2894 526878.000 -3.512e+07 6765% 21.9
966s
40999 38124 -1813455.7 512 0 526878.000 -3.512e+07 6765% 21.9
1014s
Cutting planes:
Gomory: 323
Explored 41000 nodes (982458 simplex iterations) in 1014.80 seconds
Thread count was 2 (of 2 available processors)
Optimal solution found (tolerance 1.00e-09)
Best objective 5.268780000000e+05, best bound 5.268780000000e+05, gap
0.0%
___________________________________________________________________________
Optimize a model with 70980 rows, 74564 columns and 162234 nonzeros
Presolve removed 63333 rows and 69865 columns
Presolve time: 1.42s
Presolved: 7647 rows, 4699 columns, 19879 nonzeros
Variable types: 0 continuous, 4699 integer (2414 binary)
Optimize a model with 7647 rows, 4699 columns and 19879 nonzeros
Deterministic concurrent optimizer: dual simplex and barrier
Showing barrier log only...
Presolve removed 2766 rows and 26 columns
Presolved: 4881 rows, 7422 columns, 16893 nonzeros
Root barrier log...
Ordering time: 0.21s
Barrier statistics:
Dense cols : 12
AA' NZ : 2.051e+04
Factor NZ : 1.976e+05 (roughly 7 MBytes of memory)
Factor Ops : 2.047e+07 (less than 1 second per iteration)
Threads : 1
Objective Residual
Iter Primal Dual Primal Dual Compl
Time
0 -4.04463939e+07 1.26970813e+08 2.36e+07 2.93e+03 3.02e+06
0s
1 2.10575313e+07 -1.22017448e+08 1.30e+06 2.61e+02 2.01e+05
0s
2 -1.62778890e+07 -8.95299429e+07 1.96e+05 1.40e+01 2.67e+04
0s
3 -3.47154532e+07 -5.39830742e+07 4.96e+04 1.30e+00 6.24e+03
1s
4 -4.11616654e+07 -4.68814555e+07 7.98e+03 1.33e-01 1.14e+03
1s
5 -4.15963879e+07 -4.44529945e+07 3.32e+03 4.57e-02 4.82e+02
1s
6 -4.14965922e+07 -4.27152346e+07 1.80e+03 8.19e-03 2.19e+02
1s
7 -4.14551097e+07 -4.20904657e+07 7.97e+02 2.92e-03 9.92e+01
1s
8 -4.14473039e+07 -4.17439343e+07 3.18e+02 1.11e-03 4.08e+01
1s
9 -4.14381193e+07 -4.15373501e+07 1.20e+02 3.10e-04 1.35e+01
1s
10 -4.14376858e+07 -4.15163767e+07 1.08e+02 2.45e-04 1.13e+01
1s
11 -4.14374509e+07 -4.15057935e+07 1.01e+02 2.15e-04 1.02e+01
1s
12 -4.14372642e+07 -4.14951783e+07 9.48e+01 1.91e-04 9.28e+00
1s
13 -4.14371546e+07 -4.14822117e+07 9.20e+01 1.78e-04 8.81e+00
1s
14 -4.14369898e+07 -4.14763951e+07 9.01e+01 1.76e-04 8.67e+00
1s
15 -4.14368544e+07 -4.14415643e+07 8.94e+01 1.68e-04 8.43e+00
1s
16 -4.14351701e+07 -4.14290998e+07 8.66e+01 1.65e-04 8.22e+00
1s
17 -4.14297028e+07 -4.14070382e+07 7.90e+01 1.14e-04 6.57e+00
1s
18 -4.14290710e+07 -4.13971781e+07 7.81e+01 1.12e-04 6.49e+00
2s
19 -4.14261714e+07 -4.13950410e+07 7.50e+01 1.08e-04 6.23e+00
2s
20 -4.14160017e+07 -4.13882247e+07 6.41e+01 8.38e-05 5.14e+00
2s
21 -4.14126054e+07 -4.13652264e+07 6.05e+01 6.11e-05 4.33e+00
2s
22 -4.14119550e+07 -4.13540158e+07 5.99e+01 5.96e-05 4.27e+00
2s
23 -4.14111480e+07 -4.13057277e+07 5.90e+01 5.81e-05 4.19e+00
2s
24 -4.14102415e+07 -4.09609151e+07 5.85e+01 5.43e-05 4.07e+00
2s
25 -4.14012942e+07 -4.07536429e+07 5.85e+01 5.43e-05 4.69e+00
2s
26 -4.13131196e+07 -4.07787203e+07 5.11e+01 5.19e-05 4.71e+00
2s
27 -4.12909210e+07 -4.08576890e+07 4.92e+01 3.77e-05 5.72e+00
2s
28 -4.12415027e+07 -4.07136776e+07 4.51e+01 3.20e-05 3.90e+00
2s
29 -4.12322948e+07 -4.06371610e+07 4.43e+01 3.12e-05 3.84e+00
2s
30 -4.12268671e+07 -4.04829495e+07 4.39e+01 3.06e-05 3.79e+00
2s
31 -4.12146778e+07 -4.05117792e+07 4.33e+01 3.06e-05 3.92e+00
2s
32 -4.11671857e+07 -4.05790386e+07 4.05e+01 2.65e-05 4.08e+00
2s
33 -4.11470801e+07 -4.05921649e+07 3.94e+01 2.22e-05 4.25e+00
2s
34 -4.11247700e+07 -4.04282438e+07 3.84e+01 1.98e-05 3.64e+00
2s
35 -4.11091517e+07 -4.03702533e+07 3.75e+01 1.90e-05 3.52e+00
2s
36 -4.10550920e+07 -4.03381699e+07 3.57e+01 1.89e-05 4.54e+00
2s
37 -4.10527322e+07 -4.02840346e+07 3.56e+01 1.89e-05 4.56e+00
2s
38 -4.10002793e+07 -4.02841888e+07 3.32e+01 1.63e-05 4.21e+00
2s
39 -4.09847543e+07 -4.02666744e+07 3.26e+01 1.60e-05 4.19e+00
2s
40 -4.09361741e+07 -4.02606038e+07 3.05e+01 1.40e-05 3.98e+00
2s
41 -4.09224023e+07 -4.02554479e+07 2.99e+01 1.39e-05 3.92e+00
2s
42 -4.09133478e+07 -4.02506157e+07 2.95e+01 1.34e-05 3.84e+00
2s
43 -4.08875108e+07 -4.02407748e+07 2.84e+01 1.29e-05 3.68e+00
3s
Barrier performed 43 iterations in 2.51 seconds
Optimization interrupted
Concurrent spin time: 1.16s (can be avoided by choosing Method=3)
Solved with dual simplex
Solved in 4623 iterations and 2.52 seconds
Optimal objective -3.787085689e+07
Root relaxation: objective -3.787086e+07, 4623 iterations, 2.52
seconds
Nodes | Current Node | Objective Bounds |
Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/
Node Time
0 0 -3.787e+07 0 612 - -3.787e+07 -
- 6s
0 0 -3.714e+07 0 2912 - -3.714e+07 -
- 8s
0 0 -3.714e+07 0 2899 - -3.714e+07 -
- 9s
0 0 -3.714e+07 0 2899 - -3.714e+07 -
- 9s
0 0 -3.714e+07 0 2873 - -3.714e+07 - -
11s
H 0 0 2638768.0000 -3.714e+07 1508% -
12s
0 2 -3.714e+07 0 2843 2638768.00 -3.714e+07 1508% -
15s
H 63 64 2517684.0000 -3.713e+07 1575% 18.7
18s
179 180 -3.372e+07 79 762 2517684.00 -3.713e+07 1575% 10.4
20s
516 518 -1.548e+07 255 519 2517684.00 -3.713e+07 1575% 11.2
25s
1003 1004 -8402623.7 496 278 2517684.00 -3.713e+07 1575% 10.5
30s
H 1004 1005 2220434.0000 -3.713e+07 1772% 10.5
30s
* 1248 1236 558 1155102.0000 -3.713e+07 3314% 11.0
32s
1448 1402 -3.578e+07 24 2825 1155102.00 -3.705e+07 3308% 12.1
35s
H 1549 1411 906129.00000 -3.705e+07 4189% 11.9
42s
H 1549 1341 559340.00000 -3.705e+07 6725% 11.9
43s
1551 1342 -6388026.0 554 2811 559340.000 -3.704e+07 6722% 11.9
50s
...
332896 280015 -1.827e+07 78 2839 452004.000 -3.186e+07 7150% 30.7
7130s
333212 280330 -9876705.0 211 2729 452004.000 -3.186e+07 7150% 30.7
7135s
333519 280603 -4214932.6 440 2691 452004.000 -3.186e+07 7150% 30.7
7140s
333861 280921 -1.832e+07 59 2809 452004.000 -3.186e+07 7149% 30.7
7145s
334049 281066 -667767.66 82 2214 452004.000 -3.186e+07 7149% 30.7
7150s
334331 281328 -1.601e+07 136 2823 452004.000 -3.185e+07 7146% 30.7
7155s
334619 281616 -8627133.9 208 2778 452004.000 -3.185e+07 7146% 30.7
7160s
335115 282081 -2924337.3 470 2575 452004.000 -3.185e+07 7146% 30.6
7166s
335481 282394 -35956.217 711 2344 452004.000 -3.185e+07 7146% 30.6
7170s
335801 282672 -9930598.6 184 2761 452004.000 -3.183e+07 7141% 30.6
7175s
336212 283083 -3371246.3 378 2682 452004.000 -3.183e+07 7141% 30.6
7180s
336626 283486 -160545.27 600 2455 452004.000 -3.182e+07 7141% 30.6
7185s
336868 283686 -1.381e+07 166 2833 452004.000 -3.182e+07 7141% 30.6
7190s
336921 283738 -1.019e+07 197 2804 452004.000 -3.182e+07 7141% 30.6
7195s
336985 283804 -7869384.2 225 2776 452004.000 -3.182e+07 7141% 30.6
7200s
Cutting planes:
Gomory: 280
MIR: 2
Explored 336989 nodes (10337308 simplex iterations) in 7200.02 seconds
Thread count was 2 (of 2 available processors)
Time limit reached
Best objective 4.520040000000e+05, best bound -3.182406691308e+07, gap
7140.6605%
I hope you can help me to find an explanation for this strange
behaviour.
Greg Glockner
Setting a time limit makes Gurobi non-deterministic; it may produce different results each time.
> Running the same program with the interactive shell I haven't observed
> the described problem.
This suggests the issue involves your Java program.
opt1234
I build the model like it is suggested in the example section for the
Java interface (e.g. MIP1.java). Afterwards I use the write-command to
save the model in a lp-file. And finally I call the optimize-function.
So there shouldn't be differences in both models (except for order of
constraints). Could the order in which the constraints are added to
the model or the timelimit cause the problem? When running this
instance without timelimit the problem wasn't observed either. Or
could there be some rounding errors?
Greg Glockner
> the model or the timelimit cause the problem? When running this
> instance without timelimit the problem wasn't observed either. Or
> could there be some rounding errors?
Possibly. Try exporting your model in MPS format instead of LP format, since Gurobi maintains all ordering and precision for MPS format but not LP format. Also, upgrade to the latest version, 4.6.0.
opt1234
solver reported 2 different optimal solutions for the same instance
(which isn't possible). If I get a report that the gurobi-solver found
an optimal solution, how can I be sure that this is actually an
optimal solution?
Greg Glockner
My previous post tried to explain this: you can get different results with a time limit. Try again with:
1. Exporting the model file to an MPS file
2. Solving the MPS file from gurobi_cl, and using another type of limit such as a MIPGap or NodeLimit.
opt1234
But how can you get wrong "optimal solutions"? I know that I can get
solutions which are not optimal if I use the time limit option. Then
the solver says something like "Time Limit reached". But in this two
cases the solver reported explicitely "Optimal solution found". This
happened long before the time limit was reached.
Greg Glockner
>>> solver reported 2 different optimal solutions for the same instance
>>> (which isn't possible). If I get a report that the gurobi-solver found
>>> an optimal solution, how can I be sure that this is actually an
>>> optimal solution?
Please upgrade to 4.6.0 to ensure that this isn't the result of some bug that wasn't fixed already.
opt1234
some bug that wasn't fixed already.
Thank you for your help. I upgraded to 4.6.0 and ran the instance six
times. So far the wrong optimal solutions didn't happen again.