Is best bound estimation always accurate as it is changing over time?
OngoingIs best bound estimation always accurate.
below are my logs
Since best bounds is changing over run time.
Gurobi 9.5.0 (win64) logging started Sat Feb 24 23:07:18 2024
Set parameter MIPGap to value 0.001
Set parameter TimeLimit to value 7200
Set parameter PreSOS2Encoding to value 1
Set parameter NonConvex to value 2
Gurobi Optimizer version 9.5.0 build v9.5.0rc5 (win64)
Gurobi Compute Server Worker version 9.5.0 build v9.5.0rc5 (win64)
Thread count: 8 physical cores, 8 logical processors, using up to 8 threads
Optimize a model with 18909 rows, 109739 columns and 690650 nonzeros
Model fingerprint: 0x73ebc018
Model has 91 SOS constraints
Model has 580 general constraints
Variable types: 107666 continuous, 2073 integer (2073 binary)
Coefficient statistics:
Matrix range [2e-06, 1e+04]
Objective range [1e+00, 1e+01]
Bounds range [1e-05, 1e+04]
RHS range [1e-05, 5e+03]
GenCon rhs range [8e-02, 4e+03]
GenCon coe range [8e-02, 4e+04]
Presolve removed 18612 rows and 10857 columns (presolve time = 5s) ...
Presolve removed 14043 rows and 8184 columns
Presolve time: 5.93s
Presolved: 4866 rows, 101555 columns, 502620 nonzeros
Presolved model has 20 SOS constraint(s)
Variable types: 100041 continuous, 1514 integer (1514 binary)
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
0 -1.4314643e+02 1.875000e+03 0.000000e+00 7s
6497 -8.6164477e+01 0.000000e+00 0.000000e+00 8s
Root relaxation: objective -8.616448e+01, 6497 iterations, 0.53 seconds (0.53 work units)
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 -86.16448 0 173 - -86.16448 - - 9s
H 0 0 0.0000000 -86.16448 - - 9s
H 0 0 -0.7531123 -86.16448 - - 11s
H 0 0 -8.4941106 -86.16448 914% - 20s
0 0 -74.96000 0 617 -8.49411 -74.96000 782% - 21s
H 0 0 -12.5657269 -74.96000 497% - 22s
0 0 -74.73443 0 608 -12.56573 -74.73443 495% - 24s
0 0 -74.31574 0 612 -12.56573 -74.31574 491% - 25s
H 0 0 -12.5657270 -74.31574 491% - 26s
0 0 -74.28173 0 634 -12.56573 -74.28173 491% - 27s
0 0 -74.22866 0 631 -12.56573 -74.22866 491% - 28s
0 0 -74.22860 0 633 -12.56573 -74.22860 491% - 28s
0 0 -74.21367 0 666 -12.56573 -74.21367 491% - 29s
0 0 -74.12817 0 656 -12.56573 -74.12817 490% - 29s
0 0 -74.12817 0 669 -12.56573 -74.12817 490% - 30s
0 0 -74.12817 0 669 -12.56573 -74.12817 490% - 30s
0 0 -74.11028 0 666 -12.56573 -74.11028 490% - 31s
0 0 -74.11028 0 677 -12.56573 -74.11028 490% - 31s
0 0 -74.05054 0 683 -12.56573 -74.05054 489% - 32s
0 0 -73.90635 0 599 -12.56573 -73.90635 488% - 35s
0 2 -73.90635 0 531 -12.56573 -73.90635 488% - 40s
H 31 40 -24.0005568 -73.90635 208% 691 46s
H 38 40 -25.6919285 -73.90635 188% 626 46s
106 115 -44.46274 13 478 -25.69193 -73.90635 188% 457 50s
281 252 -43.34907 24 406 -25.69193 -73.90635 188% 331 55s
H 284 252 -25.6919348 -73.90635 188% 330 55s
H 287 252 -25.6919854 -73.90635 188% 329 55s
541 450 infeasible 53 -25.69199 -73.90635 188% 270 60s
* 819 583 152 -31.8767763 -73.90635 132% 236 63s
930 763 -36.77904 51 237 -31.87678 -73.90635 132% 226 65s
1419 1072 -70.51226 11 608 -31.87678 -73.90635 132% 190 70s
H 1491 1020 -32.3636000 -73.90635 128% 189 78s
1492 1020 -43.06535 101 198 -32.36360 -73.90635 128% 189 88s
1493 1021 -35.55107 80 878 -32.36360 -73.90635 128% 189 91s
H 1494 971 -32.7190879 -73.90635 126% 189 93s
1497 973 -71.09120 15 972 -32.71909 -73.90635 126% 188 95s
1499 974 -39.42491 16 751 -32.71909 -73.90635 126% 188 100s
H 1500 928 -33.0270090 -73.90635 124% 207 107s
1501 928 -73.90635 16 775 -33.02701 -73.90635 124% 208 116s
1506 936 -68.48481 18 635 -33.02701 -73.90635 124% 209 121s
1528 950 -65.21858 20 739 -33.02701 -73.90635 124% 217 125s
H 1536 907 -34.8191778 -73.90635 112% 220 131s
H 1538 862 -34.8695244 -73.90635 112% 219 131s
H 1539 820 -36.3776213 -73.90635 103% 219 131s
H 1541 779 -38.2465309 -73.90635 93.2% 220 131s
1573 802 -62.74636 23 581 -38.24653 -73.90635 93.2% 220 138s
H 1579 763 -47.3729984 -73.90635 56.0% 221 138s
1582 770 -63.75732 24 690 -47.37300 -73.90635 56.0% 222 141s
1683 825 -61.82060 30 726 -47.37300 -73.90635 56.0% 225 146s
1942 937 -51.71964 50 471 -47.37300 -73.90635 56.0% 215 150s
2319 1070 -49.72295 70 541 -47.37300 -73.90635 56.0% 197 155s
2559 1069 -49.65899 94 332 -47.37300 -73.90635 56.0% 190 160s
2869 1148 -73.50782 24 958 -47.37300 -73.90635 56.0% 183 165s
3128 1148 infeasible 33 -47.37300 -73.90635 56.0% 184 170s
3158 1206 -73.90635 22 743 -47.37300 -73.90635 56.0% 184 177s
H 3165 1128 -48.7358956 -73.90635 51.6% 184 177s
H 3230 677 -60.2759104 -73.90635 22.6% 185 177s
H 3238 581 -61.2312445 -73.90635 20.7% 184 177s
3261 557 -73.58447 29 1019 -61.23124 -73.90635 20.7% 189 181s
3319 564 -71.46017 32 1052 -61.23124 -73.90635 20.7% 193 186s
3365 563 -71.32791 33 1047 -61.23124 -73.90635 20.7% 194 229s
3384 570 -70.83037 35 993 -61.23124 -73.90635 20.7% 196 265s
3606 781 -62.24525 76 757 -61.23124 -73.90635 20.7% 196 271s
3862 848 -73.32906 27 976 -61.23124 -73.90635 20.7% 198 276s
3953 919 -63.85765 30 943 -61.23124 -73.90635 20.7% 204 281s
4060 935 -63.08316 38 891 -61.23124 -73.90635 20.7% 205 298s
4078 1100 -62.96805 41 890 -61.23124 -73.90635 20.7% 205 301s
H 4308 1106 -61.2361594 -73.90635 20.7% 202 313s
H 4309 1065 -61.4308033 -73.90635 20.3% 202 313s
H 4310 988 -61.9383824 -73.90635 19.3% 202 313s
H 4317 981 -62.1061398 -73.90635 19.0% 202 313s
4318 990 cutoff 74 -62.10614 -73.90635 19.0% 202 347s
H 4356 1003 -62.1068280 -73.90635 19.0% 203 356s
H 4372 986 -62.3705409 -73.90635 18.5% 204 356s
4373 1007 -69.65975 31 1115 -62.37054 -73.90635 18.5% 204 374s
4428 1095 -66.81069 34 1045 -62.37054 -73.90635 18.5% 206 377s
4603 1100 -64.77065 59 901 -62.37054 -73.90635 18.5% 208 389s
4612 1115 -64.75949 60 777 -62.37054 -73.90635 18.5% 208 414s
4657 1136 -64.75112 63 781 -62.37054 -73.90635 18.5% 210 431s
4682 1293 -64.74514 64 780 -62.37054 -73.90635 18.5% 211 435s
4950 1406 -67.03281 25 1034 -62.37054 -73.90635 18.5% 209 440s
5420 1476 infeasible 42 -62.37054 -73.90635 18.5% 208 466s
H 5421 1461 -62.4157810 -73.90635 18.4% 208 466s
H 5422 1241 -63.1703016 -73.90635 17.0% 208 466s
5430 1276 infeasible 43 -63.17030 -73.90635 17.0% 208 496s
5678 1357 -63.46905 79 402 -63.17030 -73.90635 17.0% 212 503s
5811 1385 infeasible 42 -63.17030 -73.90635 17.0% 213 512s
5893 1421 infeasible 47 -63.17030 -73.90635 17.0% 214 524s
H 5907 1421 -63.1703089 -73.90635 17.0% 213 524s
6020 1462 infeasible 40 -63.17031 -73.90635 17.0% 215 564s
H 6060 1333 -63.6084275 -73.90635 16.2% 216 564s
6118 1561 -66.20065 40 944 -63.60843 -73.90635 16.2% 216 568s
H 6555 1564 -63.6084317 -73.90635 16.2% 210 580s
H 6557 1564 -63.6084328 -73.90635 16.2% 210 580s
H 6558 1563 -63.6095677 -73.90635 16.2% 210 580s
H 6563 1545 -63.6495323 -73.90635 16.1% 211 580s
6720 1560 cutoff 41 -63.64953 -73.90635 16.1% 212 628s
6814 1678 -65.49488 34 966 -63.64953 -73.90635 16.1% 214 639s
H 7010 1678 -63.6505477 -73.90635 16.1% 215 639s
7114 1713 infeasible 49 -63.65055 -73.90635 16.1% 215 661s
7255 1707 infeasible 36 -63.65055 -73.90635 16.1% 219 666s
7428 1745 -66.84185 24 959 -63.65055 -73.90635 16.1% 223 671s
7645 1766 -65.84239 31 959 -63.65055 -73.90635 16.1% 224 697s
7829 1903 -64.15927 42 936 -63.65055 -73.90635 16.1% 225 712s
H 7913 1902 -63.6505619 -73.90635 16.1% 225 712s
H 8196 1670 -63.8368258 -73.90635 15.8% 224 728s
H 8197 1667 -63.8394552 -73.90635 15.8% 224 728s
H 8199 1667 -63.8396327 -73.90635 15.8% 224 728s
H 8203 1667 -63.8399081 -73.90635 15.8% 224 728s
8207 1686 cutoff 30 -63.83991 -73.79379 15.6% 224 747s
8361 1716 -67.84162 29 1068 -63.83991 -73.51272 15.2% 227 806s
8495 2014 -64.75705 50 873 -63.83991 -73.11450 14.5% 227 821s
9108 2106 -67.82790 31 1092 -63.83991 -71.87478 12.6% 221 828s
H 9512 2112 -63.8401207 -70.89101 11.0% 222 838s
H 9514 2112 -63.8401446 -70.89101 11.0% 222 838s
9522 2147 cutoff 33 -63.84014 -70.89101 11.0% 222 890s
9730 2149 infeasible 29 -63.84014 -70.70349 10.8% 223 907s
H 9731 2149 -63.8402957 -70.70349 10.8% 223 907s
H 9736 2144 -63.8414139 -70.70349 10.7% 223 907s
9839 2157 -65.82793 28 1029 -63.84141 -70.26288 10.1% 223 931s
10063 2407 -66.19531 50 840 -63.84141 -70.24134 10.0% 224 940s
10840 2418 -64.24741 44 767 -63.84141 -68.33356 7.04% 219 968s
10886 2633 -67.95392 52 781 -63.84141 -68.31895 7.01% 220 976s
11259 3275 -68.19926 50 778 -63.84141 -68.27329 6.94% 217 986s
12509 3277 infeasible 39 -63.84141 -67.86882 6.31% 210 1010s
12550 3817 cutoff 55 -63.84141 -67.86688 6.31% 210 1020s
13705 3995 -66.37588 58 871 -63.84141 -67.83075 6.25% 205 1031s
14729 3910 -66.70487 64 732 -63.84141 -67.81296 6.22% 205 1051s
15048 3768 -66.53529 63 623 -63.84141 -67.80772 6.21% 206 1066s
16360 3752 -66.45467 62 665 -63.84141 -67.52555 5.77% 202 1083s
16539 3675 -66.04901 37 692 -63.84141 -67.46467 5.68% 203 1097s
Cutting planes:
Learned: 1
Cover: 18
Implied bound: 74
Clique: 2
MIR: 54
Flow cover: 52
GUB cover: 9
Network: 21
RLT: 5
Relax-and-lift: 27
BQP: 1
Explored 17590 nodes (3517453 simplex iterations) in 1097.77 seconds (1623.21 work units)
Thread count was 8 (of 8 available processors)
Solution count 10: -63.8414 -63.8403 -63.8401 ... -63.6505
Solve interrupted
Warning: max constraint violation (8.3825e-06) exceeds tolerance
Best objective -6.384141392220e+01, best bound -6.729183685038e+01, gap 5.4047%
User-callback calls 623, time in user-callback 0.00 sec
Gurobi Optimizer version 9.5.0 build v9.5.0rc5 (win64)
Gurobi Compute Server Worker version 9.5.0 build v9.5.0rc5 (win64)
Thread count: 8 physical cores, 8 logical processors, using up to 8 threads
Optimize a model with 18909 rows, 109739 columns and 690650 nonzeros
Model fingerprint: 0x270ed3ed
Model has 91 SOS constraints
Model has 580 general constraints
Variable types: 107666 continuous, 2073 integer (2073 binary)
Coefficient statistics:
Matrix range [2e-06, 1e+04]
Objective range [1e+00, 1e+01]
Bounds range [1e-05, 1e+04]
RHS range [1e-05, 5e+03]
GenCon rhs range [8e-02, 4e+03]
GenCon coe range [8e-02, 4e+04]
MIP start from previous solve did not produce a new incumbent solution
Presolve removed 18378 rows and 4784 columns (presolve time = 6s) ...
Presolve removed 13633 rows and 2055 columns
Presolve time: 5.70s
Presolved: 5276 rows, 107684 columns, 529695 nonzeros
Presolved model has 87 SOS constraint(s)
Variable types: 106050 continuous, 1634 integer (1634 binary)
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
0 -1.5132529e+02 2.255615e+03 0.000000e+00 7s
6954 -8.6770792e+01 0.000000e+00 0.000000e+00 8s
Root relaxation: objective -8.677079e+01, 6954 iterations, 0.88 seconds (1.01 work units)
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 -86.77079 0 222 - -86.77079 - - 9s
H 0 0 0.0000000 -86.77079 - - 10s
H 0 0 -3.9799743 -84.59780 2026% - 34s
0 0 -84.59780 0 516 -3.97997 -84.59780 2026% - 36s
H 0 0 -3.9799744 -84.59780 2026% - 39s
0 0 -84.59780 0 481 -3.97997 -84.59780 2026% - 39s
0 0 -84.59780 0 467 -3.97997 -84.59780 2026% - 41s
H 0 0 -3.9799744 -84.59780 2026% - 42s
0 0 -84.59010 0 494 -3.97997 -84.59010 2025% - 47s
0 0 -84.59010 0 523 -3.97997 -84.59010 2025% - 49s
0 0 -84.59010 0 514 -3.97997 -84.59010 2025% - 51s
0 0 -84.59010 0 533 -3.97997 -84.59010 2025% - 52s
H 0 0 -12.3459240 -84.59010 585% - 54s
0 0 -84.59010 0 493 -12.34592 -84.59010 585% - 55s
0 0 -84.59010 0 503 -12.34592 -84.59010 585% - 56s
0 0 -84.59010 0 260 -12.34592 -84.59010 585% - 59s
0 2 -84.59010 0 238 -12.34592 -84.59010 585% - 76s
7 14 -71.52457 3 417 -12.34592 -84.59010 585% 2054 80s
23 30 -71.52457 5 391 -12.34592 -84.59010 585% 1690 85s
H 31 38 -12.3461411 -84.59010 585% 1499 91s
H 35 38 -14.3302488 -84.59010 490% 1451 91s
39 46 -71.52457 6 422 -14.33025 -84.59010 490% 1391 105s
82 96 -71.42375 9 384 -14.33025 -84.59010 490% 1037 110s
195 201 -67.46762 15 447 -14.33025 -84.59010 490% 648 115s
319 299 -61.50330 21 455 -14.33025 -84.59010 490% 510 120s
538 466 -60.10203 29 421 -14.33025 -84.59010 490% 377 125s
587 494 -59.48180 33 443 -14.33025 -84.59010 490% 366 139s
H 591 494 -14.3302488 -84.59010 490% 364 139s
629 537 -59.25440 36 408 -14.33025 -84.59010 490% 353 144s
H 667 487 -23.9517379 -84.59010 253% 340 144s
688 549 -58.37307 39 449 -23.95174 -84.59010 253% 336 146s
919 711 -58.31323 57 475 -23.95174 -84.59010 253% 303 151s
1050 876 -73.13676 13 372 -23.95174 -84.59010 253% 299 157s
1160 977 -72.70904 14 370 -23.95174 -84.59010 253% 286 160s
1298 1022 -46.55821 29 355 -23.95174 -84.59010 253% 270 167s
H 1489 1132 -23.9517632 -84.59010 253% 252 169s
1526 1133 -65.84837 59 209 -23.95176 -84.59010 253% 246 188s
1528 1134 -34.09457 23 79 -23.95176 -84.59010 253% 246 204s
1529 1135 -84.59010 10 752 -23.95176 -84.59010 253% 246 209s
H 1529 1078 -24.1555601 -84.59010 250% 246 210s
H 1532 1026 -30.0732380 -84.59010 181% 245 217s
1534 1027 -30.07324 30 774 -30.07324 -84.59010 181% 245 220s
1535 1028 -72.43531 37 763 -30.07324 -84.59010 181% 245 228s
1536 1029 -82.30181 15 114 -30.07324 -84.59010 181% 245 232s
H 1536 977 -30.0732381 -84.59010 181% 245 237s
1538 980 -71.52457 11 94 -30.07324 -84.59010 181% 273 250s
1543 987 -71.52457 13 92 -30.07324 -84.58055 181% 273 273s
1549 993 -69.38961 14 297 -30.07324 -84.58026 181% 274 290s
1565 1004 -69.38961 15 353 -30.07324 -84.58026 181% 278 300s
H 1566 955 -30.5643425 -84.58026 177% 278 300s
H 1567 907 -30.9384093 -84.58026 173% 278 300s
1608 938 -69.38961 18 364 -30.93841 -84.58026 173% 280 306s
1716 1015 -69.38961 26 307 -30.93841 -84.58026 173% 284 310s
1794 1039 -61.50523 30 377 -30.93841 -84.58026 173% 283 315s
H 1797 994 -30.9403169 -84.58026 173% 284 315s
H 1810 947 -30.9485249 -84.58026 173% 282 315s
1824 975 -61.50523 31 354 -30.94852 -84.58026 173% 284 338s
1859 980 -61.50523 34 335 -30.94852 -84.58026 173% 283 361s
1878 984 -56.66322 35 389 -30.94852 -84.58026 173% 282 382s
1903 991 -61.50523 36 327 -30.94852 -84.58026 173% 281 404s
H 1928 952 -34.6565141 -84.58026 144% 280 420s
1940 965 -60.94770 38 324 -34.65651 -84.58026 144% 279 443s
2070 978 -56.05524 55 331 -34.65651 -84.58026 144% 270 449s
H 2080 936 -43.1413651 -84.58026 96.1% 269 449s
2087 992 -50.52329 56 345 -43.14137 -84.58026 96.1% 268 450s
2377 948 infeasible 26 -43.14137 -84.48910 95.8% 257 459s
2397 958 -84.48910 22 503 -43.14137 -84.48910 95.8% 256 488s
2425 1088 -84.48276 24 508 -43.14137 -84.48910 95.8% 255 492s
2616 1205 -84.47901 34 437 -43.14137 -84.48910 95.8% 251 495s
2862 1304 -81.06583 42 427 -43.14137 -84.48910 95.8% 245 500s
H 3193 1163 -43.6720541 -84.48910 93.5% 236 513s
H 3194 1129 -43.7164692 -84.48910 93.3% 236 513s
H 3199 1094 -43.7361833 -84.48910 93.2% 236 514s
3203 1109 -80.69531 56 420 -43.73618 -84.48910 93.2% 236 526s
3229 1115 -80.46330 58 406 -43.73618 -84.48910 93.2% 237 538s
3260 1169 infeasible 61 -43.73618 -84.48910 93.2% 236 547s
3352 1325 infeasible 56 -43.73618 -84.48910 93.2% 235 552s
3700 1348 -80.80531 31 630 -43.73618 -84.48910 93.2% 227 560s
4002 1677 -80.80528 39 663 -43.73618 -84.48910 93.2% 223 569s
4480 1808 -79.25535 51 607 -43.73618 -84.48910 93.2% 212 573s
4702 2083 -71.84619 62 508 -43.73618 -84.48875 93.2% 209 579s
5272 2115 -71.75253 54 401 -43.73618 -84.48875 93.2% 197 582s
H 5339 2102 -47.5654097 -84.48875 77.6% 197 593s
5348 2128 -63.45665 64 339 -47.56541 -84.48875 77.6% 197 597s
5408 2328 -62.64489 66 360 -47.56541 -84.48875 77.6% 196 603s
6027 2594 -52.12001 132 236 -47.56541 -84.48875 77.6% 185 611s
6654 2732 -84.47756 41 425 -47.56541 -84.48365 77.6% 179 620s
H 6748 2447 -60.7059490 -84.48365 39.2% 178 620s
H 6773 2447 -60.7060057 -84.48365 39.2% 178 620s
6928 2964 -84.47830 28 429 -60.70601 -84.48365 39.2% 177 633s
8288 2962 infeasible 53 -60.70601 -84.48262 39.2% 164 657s
H 8291 2869 -61.5503285 -84.48262 37.3% 164 657s
H 8292 2836 -62.2979191 -84.48262 35.6% 164 657s
8306 2864 -84.48246 30 450 -62.29792 -84.48246 35.6% 164 664s
8402 2893 -84.48246 32 438 -62.29792 -84.48246 35.6% 163 679s
8483 3302 -84.47737 34 424 -62.29792 -84.48246 35.6% 163 692s
10199 3324 infeasible 45 -62.29792 -84.48060 35.6% 149 707s
10279 3343 infeasible 45 -62.29792 -84.48041 35.6% 149 728s
10339 3873 infeasible 38 -62.29792 -84.48024 35.6% 149 739s
11494 4370 -78.26365 50 352 -62.29792 -84.47901 35.6% 148 750s
12549 4409 cutoff 54 -62.29792 -84.47901 35.6% 148 757s
12683 4748 -69.94033 49 371 -62.29792 -84.47901 35.6% 149 824s
H12878 4748 -62.2979192 -84.47900 35.6% 150 824s
13456 4783 -69.89089 39 497 -62.29792 -84.47881 35.6% 151 848s
13545 4846 -66.61381 47 382 -62.29792 -84.47881 35.6% 152 858s
13705 5259 -82.34274 45 370 -62.29792 -84.47878 35.6% 153 869s
14649 5457 -69.72218 51 357 -62.29792 -84.47875 35.6% 155 879s
15193 5932 -81.82530 44 514 -62.29792 -84.47875 35.6% 154 891s
16212 6054 -84.47871 35 515 -62.29792 -84.47871 35.6% 157 907s
16464 6673 -68.52089 54 455 -62.29792 -84.47871 35.6% 158 921s
17736 7212 -79.32270 47 282 -62.29792 -84.47871 35.6% 160 935s
18875 7252 -70.21728 41 365 -62.29792 -84.47871 35.6% 163 958s
18969 7875 -67.48576 53 333 -62.29792 -84.47871 35.6% 164 986s
H19142 7873 -62.3226592 -84.47871 35.6% 164 986s
20306 8031 -78.11400 76 331 -62.32266 -84.47871 35.6% 166 1007s
20556 8679 -75.70715 100 363 -62.32266 -84.47871 35.6% 166 1024s
21927 9283 -83.26101 63 492 -62.32266 -84.47871 35.6% 168 1040s
23182 9363 cutoff 105 -62.32266 -84.47871 35.6% 169 1075s
H23373 9434 -62.3764299 -84.47871 35.4% 169 1128s
H23374 9399 -62.5746855 -84.47871 35.0% 169 1128s
H23375 9374 -62.6817004 -84.47871 34.8% 169 1128s
23584 10002 -77.80263 105 403 -62.68170 -84.47871 34.8% 170 1147s
24950 10308 -73.47961 62 370 -62.68170 -84.47871 34.8% 172 1161s
25512 11048 -82.45649 46 387 -62.68170 -84.47871 34.8% 173 1191s
26885 11148 -83.19178 41 710 -62.68170 -84.47871 34.8% 173 1205s
27203 11733 -84.47871 41 504 -62.68170 -84.47871 34.8% 173 1223s
28441 11978 -83.40216 44 497 -62.68170 -84.47871 34.8% 176 1244s
28886 13033 -82.31579 49 489 -62.68170 -84.47871 34.8% 176 1265s
30853 13693 infeasible 88 -62.68170 -84.47871 34.8% 175 1286s
32319 14459 -72.55571 53 372 -62.68170 -84.47871 34.8% 177 1319s
33929 14556 -81.96594 56 480 -62.68170 -84.47871 34.8% 178 1354s
34149 15353 -79.69737 59 455 -62.68170 -84.47871 34.8% 178 1375s
35891 16015 cutoff 58 -62.68170 -84.47871 34.8% 180 1399s
H37389 16018 -62.6843645 -84.47871 34.8% 180 1528s
H37394 16004 -62.7314628 -84.47871 34.7% 180 1528s
H37400 15997 -62.7408236 -84.47871 34.6% 181 1528s
37408 16139 -66.25122 109 274 -62.74082 -84.47871 34.6% 181 1541s
37721 16703 infeasible 34 -62.74082 -84.47871 34.6% 182 1565s
39219 16892 -77.41150 57 410 -62.74082 -84.47871 34.6% 182 1580s
H39560 17166 -62.7451136 -84.47871 34.6% 182 1649s
H39648 17166 -62.7451805 -84.47854 34.6% 182 1649s
H39750 17117 -62.8189825 -84.47851 34.5% 182 1649s
H40068 17223 -62.8376566 -84.47851 34.4% 182 1733s
40459 17354 -79.50664 42 547 -62.83766 -84.47842 34.4% 183 1799s
H40496 17232 -63.0611746 -84.47842 34.0% 183 1799s
40678 18052 -78.25136 55 660 -63.06117 -84.47830 34.0% 183 1822s
42153 18407 -84.47820 34 647 -63.06117 -84.47820 34.0% 184 1929s
H42304 18407 -63.0611764 -84.47820 34.0% 184 1929s
42732 19146 infeasible 40 -63.06118 -84.47820 34.0% 184 1952s
44214 20140 -67.49020 53 536 -63.06118 -84.47820 34.0% 185 1975s
45945 20316 infeasible 48 -63.06118 -84.47820 34.0% 185 1990s
46287 21253 -77.92751 51 632 -63.06118 -84.47820 34.0% 185 2014s
47993 21903 -65.25657 71 457 -63.06118 -84.47820 34.0% 186 2071s
49464 22000 infeasible 124 -63.06118 -84.47820 34.0% 185 2089s
49673 22845 -73.90218 68 491 -63.06118 -84.47820 34.0% 185 2115s
51602 23617 -84.47767 32 410 -63.06118 -84.47820 34.0% 184 2153s
53474 23927 -67.51688 79 362 -63.06118 -84.47820 34.0% 183 2174s
54213 23927 -69.83296 42 357 -63.06118 -84.47820 34.0% 183 2175s
54249 24590 -66.43094 54 467 -63.06118 -84.47820 34.0% 183 2202s
55920 25384 -79.84430 36 358 -63.06118 -84.47785 34.0% 183 2229s
57325 25455 cutoff 41 -63.06118 -84.47784 34.0% 183 2254s
57498 26174 -79.29190 44 586 -63.06118 -84.47784 34.0% 183 2278s
58787 27071 -81.30250 47 469 -63.06118 -84.47784 34.0% 183 2310s
60419 27249 cutoff 64 -63.06118 -84.47784 34.0% 182 2330s
60718 27715 -68.27568 60 480 -63.06118 -84.47784 34.0% 182 2397s
H60838 27537 -63.1753142 -84.47784 33.7% 182 2398s
H61136 25615 -64.4274140 -84.47784 31.1% 182 2399s
61633 25654 -74.38729 61 507 -64.42741 -84.47784 31.1% 182 2426s
61789 26224 -78.97243 44 469 -64.42741 -84.47784 31.1% 183 2582s
H62074 26224 -64.4274183 -84.47784 31.1% 183 2582s
62950 26333 -78.36148 47 377 -64.42742 -84.47784 31.1% 183 2608s
63318 26465 -81.66917 50 377 -64.42742 -84.47784 31.1% 183 2679s
63593 26465 -68.88597 64 355 -64.42742 -84.47782 31.1% 183 2680s
63692 27306 -83.83411 41 415 -64.42742 -84.47782 31.1% 183 2716s
65370 27545 cutoff 52 -64.42742 -84.47782 31.1% 184 2739s
65866 28298 -81.46746 44 277 -64.42742 -84.47782 31.1% 185 2774s
67669 28420 infeasible 48 -64.42742 -84.47782 31.1% 185 2877s
H67670 27865 -64.8153958 -84.47782 30.3% 185 2877s
H67731 27808 -64.8524458 -84.47782 30.3% 186 2877s
67855 28569 cutoff 52 -64.85245 -84.47782 30.3% 186 2915s
H69658 26187 -66.3957802 -84.47782 27.2% 187 3167s
69914 26261 -75.83647 59 583 -66.39578 -84.47782 27.2% 187 3203s
70157 26944 -81.19132 53 609 -66.39578 -84.47782 27.2% 187 3248s
71933 27008 cutoff 48 -66.39578 -84.47782 27.2% 188 3476s
H71935 26847 -66.4684338 -84.47782 27.1% 188 3476s
H71940 26846 -66.4695066 -84.47782 27.1% 188 3476s
72191 27068 cutoff 51 -66.46951 -84.47782 27.1% 188 3513s
72584 27572 -78.25021 60 489 -66.46951 -84.47782 27.1% 188 3682s
H72915 27571 -66.4710336 -84.47782 27.1% 188 3682s
H73136 27562 -66.4797569 -84.47782 27.1% 188 3682s
73632 28109 cutoff 50 -66.47976 -84.47782 27.1% 189 3773s
H73635 26842 -67.1251225 -84.47782 25.9% 189 3773s
74849 26944 -77.29415 48 440 -67.12512 -84.47772 25.9% 190 3807s
75204 27652 -76.36160 53 556 -67.12512 -84.47772 25.9% 190 3848s
77002 28079 -83.31593 37 389 -67.12512 -84.47772 25.9% 191 3890s
78474 28153 infeasible 48 -67.12512 -84.47769 25.9% 191 3916s
78853 28774 -78.86764 41 414 -67.12512 -84.47769 25.9% 192 3951s
80364 29214 -75.97727 96 348 -67.12512 -84.47768 25.9% 193 4042s
H80849 28310 -67.5190324 -84.47768 25.1% 193 4043s
81307 28431 -82.77806 38 440 -67.51903 -84.47768 25.1% 194 4068s
81624 29206 infeasible 54 -67.51903 -84.47768 25.1% 194 4111s
H83192 29283 -67.6365511 -84.47768 24.9% 195 4274s
H83387 29280 -67.6410797 -84.47768 24.9% 195 4274s
H83571 29107 -67.7281357 -84.47768 24.7% 195 4274s
H83659 29032 -67.7403270 -84.47768 24.7% 196 4274s
83828 29231 -83.32041 49 467 -67.74033 -84.47768 24.7% 195 4302s
84210 29998 -73.53304 53 473 -67.74033 -84.47768 24.7% 196 4345s
85840 30809 -84.47755 43 470 -67.74033 -84.47768 24.7% 196 4389s
87605 31088 -80.90182 40 447 -67.74033 -84.47768 24.7% 197 4416s
88161 31845 infeasible 69 -67.74033 -84.47768 24.7% 197 4458s
89792 32405 -68.01055 65 295 -67.74033 -84.47767 24.7% 197 4501s
H91229 32461 -67.7413859 -84.47767 24.7% 198 4677s
H91257 32458 -67.7423984 -84.47767 24.7% 198 4677s
H91278 32453 -67.7440458 -84.47767 24.7% 198 4677s
91347 32797 -84.47755 33 497 -67.74405 -84.47767 24.7% 198 4714s
92467 32867 -78.13322 39 510 -67.74405 -84.47764 24.7% 199 4739s
92758 33266 -80.33030 49 668 -67.74405 -84.47764 24.7% 199 4787s
94360 33580 cutoff 54 -67.74405 -84.47764 24.7% 200 4840s
96026 33656 -74.26887 38 427 -67.74405 -84.47764 24.7% 200 4867s
96396 34142 -75.97246 52 374 -67.74405 -84.47764 24.7% 200 4923s
98224 34514 -79.77805 38 390 -67.74405 -84.47756 24.7% 199 4964s
98918 34514 -79.82264 36 451 -67.74405 -84.47755 24.7% 200 4965s
99351 34649 -80.30220 48 527 -67.74405 -84.47755 24.7% 201 4991s
99715 35110 -84.47745 34 472 -67.74405 -84.47755 24.7% 201 5036s
H101065 35421 -67.7463783 -84.47753 24.7% 201 5222s
H101646 34926 -67.9408777 -84.47752 24.3% 202 5223s
101714 35101 -74.89234 53 452 -67.94088 -84.47752 24.3% 202 5255s
102172 35675 -79.24507 47 554 -67.94088 -84.47752 24.3% 202 5306s
103638 35846 -84.47746 29 474 -67.94088 -84.47752 24.3% 203 5334s
103954 36546 -82.50785 52 492 -67.94088 -84.47752 24.3% 203 5376s
105507 37435 -79.48139 49 337 -67.94088 -84.47752 24.3% 204 5423s
107278 37538 -77.85238 50 412 -67.94088 -84.47752 24.3% 204 5453s
107604 38152 -73.41696 54 398 -67.94088 -84.47752 24.3% 204 5543s
109021 38383 -76.92927 48 468 -67.94088 -84.47752 24.3% 205 5581s
110072 38436 -79.50682 34 538 -67.94088 -84.47750 24.3% 206 5612s
110411 38902 -79.50675 40 544 -67.94088 -84.47750 24.3% 206 5651s
111636 39548 -84.39834 39 382 -67.94088 -84.47749 24.3% 206 5697s
113171 39720 -83.01889 39 563 -67.94088 -84.47749 24.3% 206 5745s
113696 40300 -83.01888 40 564 -67.94088 -84.47749 24.3% 207 5794s
115256 40820 -82.29888 50 522 -67.94088 -84.47749 24.3% 207 5841s
116750 40828 -78.14931 48 564 -67.94088 -84.47747 24.3% 207 6418s
H116754 40809 -67.9436676 -84.47747 24.3% 207 6418s
116828 40818 -73.90326 53 599 -67.94367 -84.47747 24.3% 207 6446s
117223 41267 infeasible 42 -67.94367 -84.47747 24.3% 207 6493s
118515 41361 -77.01070 52 560 -67.94367 -84.47747 24.3% 208 6584s
H118624 41356 -67.9446323 -84.47747 24.3% 208 6585s
118837 41970 -68.50979 65 323 -67.94463 -84.47746 24.3% 208 6635s
120229 41986 -84.33268 45 595 -67.94463 -84.47745 24.3% 208 6746s
120572 42395 -82.27792 45 371 -67.94463 -84.47745 24.3% 209 6787s
121637 42467 cutoff 43 -67.94463 -84.47745 24.3% 210 6820s
122058 43167 -82.34248 42 413 -67.94463 -84.47745 24.3% 210 6876s
123484 43317 -82.18755 43 424 -67.94463 -84.47745 24.3% 211 6912s
123913 43919 -77.46534 56 635 -67.94463 -84.47745 24.3% 212 6967s
125368 43923 -83.01889 41 437 -67.94463 -84.47745 24.3% 213 7008s
125731 44610 cutoff 48 -67.94463 -84.47744 24.3% 213 7067s
127228 45336 -72.89804 52 544 -67.94463 -84.47744 24.3% 214 7128s
128781 45435 -78.51574 50 469 -67.94463 -84.47744 24.3% 214 7156s
129047 45977 infeasible 51 -67.94463 -84.47744 24.3% 215 7200s
Cutting planes:
Learned: 1
Gomory: 4
Cover: 10
Implied bound: 34
Clique: 5
MIR: 25
Flow cover: 45
Inf proof: 5
RLT: 2
Relax-and-lift: 2
Explored 130145 nodes (28077053 simplex iterations) in 7202.32 seconds (5569.49 work units)
Thread count was 8 (of 8 available processors)
Solution count 10: -67.9446 -67.9437 -67.9409 ... -67.6411
Time limit reached
Best objective -6.794463230897e+01, best bound -8.447743916031e+01, gap 24.3328%
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The best bound, also known as the lower bound for minimization problems (or upper bound for maximization problems), is an estimate of the optimal objective value that Gurobi computes during the branch-and-bound process of Mixed Integer Programming (MIP) solving. This bound is crucial because it helps in determining how close the current solution is to the optimal solution.
From your logs, it's evident that the best bound is changing over time, which is a normal and expected behavior in the solving process. The solver continuously refines this bound as it explores more nodes in the search tree and solves more linear programming relaxations.
However, it's important to understand that the best bound is an estimate and not always a precise indicator of the optimal solution's value. Several factors can affect its accuracy:
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Problem Complexity: In more complex problems, especially those with non-linearities or large solution spaces, it might be more challenging to estimate the best bound accurately.
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Solver Parameters: The settings and parameters you choose for the solver can impact how the best bound is calculated. For example, parameters like the integrality tolerance, the emphasis on proving optimality, and the quality of the MIP start solution can influence the best bound estimation.
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Time and Node Limits: If the solving process is stopped due to time limits or node limits before reaching optimality, as seen in your logs, the best bound may not be as close to the actual optimal solution as it could be if the solver had more time or resources to run.
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Cutting Planes and Heuristics: Gurobi uses various cutting planes and heuristics to improve the solving process. The effectiveness of these techniques can vary depending on the problem, impacting the best bound's accuracy.
In your case, the final output shows a gap of approximately 24.33% between the best objective and the best bound, indicating that there is still a significant difference between the best known feasible solution and the estimated lower bound of the optimal solution. This gap can result from the solver not having enough time to fully explore the solution space or the complexity of the problem hindering a tighter bound estimation.
In summary, while the best bound is a valuable tool in the optimization process, it's not always an exact indicator of the optimal solution's value, especially in more complex problems or when the solver's exploration is limited by time or other constraints.
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How to conclude my best bound is not accurate.
Is that possible by log values which I have shared0 -
While you can't definitively say the best bound is inaccurate solely based on log values, a large optimality gap, slow convergence, and early termination of the solver are strong indicators that the best bound may not closely represent the actual optimal solution's value. It's important to interpret these logs in the context of your specific problem's characteristics and the solver's performance.
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Regarding Improvement of Best Bound and MIPGap: In the initial logs before invoking the Gurobi callback, I noticed a trend where the best bound steadily improves over time, and simultaneously, the MIPGap reduces. However, when introducing additional binary variables to the same problem, I observed that the best bound fails to show improvement. Does adjusting the MIPFocus parameter offer any assistance in addressing this issue? Additionally, I'm curious about the potential reasons behind this contrasting behavior.
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Dealing with MIP Start and Objective Incumbent Solution: I encountered the following log message: "MIP start from previous solve did not produce a new incumbent solution." My goal is to load the MIP start from a previous solve while ensuring that the objective function is preserved. How can I overcome this constraint violation and successfully achieve my objective?
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