MIP start is the optimal solution and yet I receive "MIP start did not produce a new incumbent solution"

Comments

4 comments

  • Matthias Miltenberger

    Hi Monir,

    Could you maybe share a log file of such a run? In general, it can happen that supplying a start solution - even if it is feasible - does not significantly increase the solving time. Gurobi still needs to prove optimality (up to the specified MIPGap) of the solution and this can be quite difficult, depending among other factors on how strong the LP relaxation is.

    Cheers,
    Matthias

    1
    Comment actions Permalink
  • Monir Sabbaghtorkan

    Hi Matthias, 

    Thank you for your response. I have shared the log file below. The first model is the one I run to get the optimal solution, and the second model is the one that I run with the optimal initial solution that I got from the first model. 

    I have tried to run my model for a gap 5%, but still, there is no improvement in solving time. If the time-consuming part is the process of proving optimality, do you have any idea how can I accelerate it? or how can I speed up solving this complex model in general even with the cost of sacrificing optimality?

    Thank you for your help.

     

    Bests

     

     

     


    start first model
    Changed value of parameter MIPFocus to 2
    Prev: 0 Min: 0 Max: 3 Default: 0
    Changed value of parameter Cuts to 2
    Prev: -1 Min: -1 Max: 3 Default: -1
    Optimize a model with 36488132 rows, 36700601 columns and 47451411 nonzeros
    Model has 492693 quadratic constraints
    Variable types: 36379 continuous, 36664222 integer (36655752 binary)
    Coefficient statistics:
    Matrix range [6e-04, 1e+02]
    QMatrix range [2e-04, 1e+02]
    QLMatrix range [1e-03, 3e+01]
    Objective range [1e+00, 2e+01]
    Bounds range [1e+00, 1e+02]
    RHS range [1e+00, 5e+04]
    QRHS range [1e+00, 6e+04]
    Presolve removed 875 rows and 866 columns (presolve time = 18s) ...
    Presolve removed 35721625 rows and 9275 columns (presolve time = 23s) ...
    Presolve removed 35721625 rows and 13818 columns (presolve time = 26s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 36s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 42s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 45s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 51s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 56s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 62s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 66s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 71s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 75s) ...
    Presolve removed 35722491 rows and 14684 columns (presolve time = 81s) ...
    Presolve removed 35723604 rows and 15797 columns (presolve time = 85s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 90s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 95s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 100s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 105s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 110s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 115s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 120s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 125s) ...
    Presolve removed 35724037 rows and 15797 columns (presolve time = 130s) ...
    Presolve removed 35732086 rows and 35607644 columns (presolve time = 135s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 141s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 145s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 150s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 155s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 160s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 165s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 170s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 175s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 180s) ...
    Presolve removed 35732947 rows and 35608505 columns (presolve time = 185s) ...
    Presolve removed 35744335 rows and 35617702 columns (presolve time = 192s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 195s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 200s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 205s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 210s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 215s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 220s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 225s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 230s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 235s) ...
    Presolve removed 35744336 rows and 35617702 columns (presolve time = 240s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 245s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 250s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 255s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 260s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 265s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 270s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 275s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 280s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 285s) ...
    Presolve removed 35745189 rows and 35628830 columns (presolve time = 290s) ...
    Presolve removed 35746814 rows and 35630455 columns (presolve time = 300s) ...
    Presolve removed 35746814 rows and 35630455 columns (presolve time = 311s) ...
    Presolve removed 35749251 rows and 35632892 columns (presolve time = 369s) ...
    Presolve removed 35747626 rows and 35631267 columns
    Presolve time: 369.39s
    Presolved: 4400594 rows, 4130859 columns, 15753610 nonzeros
    Variable types: 245080 continuous, 3885779 integer (3749569 binary)
    Found heuristic solution: objective 62798.000000

    Deterministic concurrent LP optimizer: primal simplex, dual simplex, and barrier
    Showing barrier log only...

    Presolve removed 258210 rows and 250000 columns (presolve time = 6s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 10s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 15s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 20s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 25s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 30s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 35s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 40s) ...
    Presolve removed 1059965 rows and 1028953 columns (presolve time = 45s) ...
    Presolve removed 1059965 rows and 1028953 columns
    Presolved: 3340629 rows, 3101906 columns, 13492070 nonzeros

    Root barrier log...

    Ordering time: 2.88s

    Barrier statistics:
    Dense cols : 1089
    AA' NZ : 8.155e+07
    Factor NZ : 1.409e+08 (roughly 4.0 GBytes of memory)
    Factor Ops : 4.754e+10 (roughly 1 second per iteration)
    Threads : 30

    Objective Residual
    Iter Primal Dual Primal Dual Compl Time
    0 5.91211808e+06 4.06997484e+07 2.08e+06 2.85e+00 3.70e+03 489s
    1 2.39250820e+06 7.25979098e+07 8.46e+05 8.89e+02 1.53e+03 492s
    2 5.10436363e+05 9.99254981e+07 1.63e+05 3.49e+03 3.20e+02 496s
    3 3.63649267e+05 9.38097546e+07 1.09e+05 4.30e+03 2.16e+02 500s
    4 2.75471823e+05 8.82589379e+07 7.70e+04 2.36e+03 1.53e+02 504s
    5 1.35387071e+05 8.20943416e+07 2.59e+04 3.21e+03 5.60e+01 507s
    6 9.60053838e+04 7.20754516e+07 1.14e+04 2.02e+03 2.70e+01 510s
    7 8.56810502e+04 5.84868343e+07 7.59e+03 1.12e+03 1.73e+01 513s
    8 7.81227897e+04 4.21162370e+07 4.82e+03 3.62e+02 9.97e+00 516s
    9 7.29613956e+04 2.47877733e+07 2.95e+03 1.28e+02 4.82e+00 521s
    10 6.76408931e+04 1.29595078e+07 1.01e+03 1.38e+02 1.80e+00 525s
    11 6.64601220e+04 6.48358183e+06 5.51e+02 7.46e+01 8.15e-01 529s
    12 6.61487666e+04 4.03272544e+06 4.14e+02 7.85e+01 4.87e-01 533s
    13 6.58661046e+04 2.56191353e+06 2.75e+02 2.16e+02 2.94e-01 538s
    14 6.56926278e+04 1.80500292e+06 1.85e+02 1.44e+02 1.98e-01 543s
    15 6.56121811e+04 1.32792631e+06 1.27e+02 1.05e+02 1.41e-01 548s
    16 6.56112523e+04 9.94820789e+05 1.01e+02 9.45e+01 1.03e-01 552s
    17 6.57047573e+04 8.68189300e+05 7.91e+01 8.10e+01 8.78e-02 556s
    18 6.58154019e+04 7.24737482e+05 6.12e+01 6.57e+01 7.15e-02 561s
    19 6.59973189e+04 4.07080792e+05 4.44e+01 3.31e+01 3.68e-02 566s
    20 6.62984219e+04 2.83787898e+05 2.86e+01 2.01e+01 2.33e-02 572s
    21 6.64503712e+04 2.56604276e+05 2.51e+01 1.76e+01 2.03e-02 576s
    22 6.68399598e+04 2.00471751e+05 2.03e+01 1.23e+01 1.42e-02 583s
    23 6.72451793e+04 1.62015766e+05 1.67e+01 8.61e+00 1.01e-02 588s
    24 6.75643734e+04 1.34165692e+05 1.46e+01 5.93e+00 7.08e-03 594s
    25 6.81522793e+04 1.16758163e+05 1.15e+01 4.25e+00 5.16e-03 599s
    26 6.86966328e+04 1.07942242e+05 9.38e+00 3.38e+00 4.16e-03 603s
    27 6.91034036e+04 9.93734350e+04 8.15e+00 2.54e+00 3.21e-03 607s
    28 6.94032174e+04 9.33113010e+04 7.36e+00 1.95e+00 2.54e-03 610s
    29 6.99843487e+04 8.80145317e+04 5.97e+00 1.43e+00 1.91e-03 612s
    30 7.03200308e+04 8.41051912e+04 5.25e+00 1.04e+00 1.46e-03 615s
    31 7.05807625e+04 8.20822630e+04 4.67e+00 8.42e-01 1.22e-03 618s
    32 7.12855300e+04 7.91503036e+04 3.39e+00 5.30e-01 8.34e-04 621s
    33 7.17162590e+04 7.64538614e+04 2.63e+00 2.77e-01 5.03e-04 625s
    34 7.21667217e+04 7.53720810e+04 1.89e+00 1.72e-01 3.40e-04 628s
    35 7.22772419e+04 7.50523019e+04 1.71e+00 1.42e-01 2.95e-04 631s
    36 7.23600398e+04 7.49921869e+04 1.58e+00 1.36e-01 2.79e-04 633s
    37 7.24142602e+04 7.49110885e+04 1.49e+00 1.29e-01 2.65e-04 635s
    38 7.25909243e+04 7.47088698e+04 1.23e+00 1.10e-01 2.25e-04 638s
    39 7.26499596e+04 7.45337280e+04 1.13e+00 9.43e-02 2.00e-04 641s
    40 7.27527302e+04 7.44063412e+04 9.80e-01 8.32e-02 1.76e-04 644s
    41 7.28321472e+04 7.42486010e+04 8.54e-01 6.93e-02 1.50e-04 648s
    42 7.28852776e+04 7.39519459e+04 7.73e-01 4.39e-02 1.13e-04 651s
    43 7.29887921e+04 7.38487422e+04 5.97e-01 3.45e-02 9.15e-05 654s
    44 7.32336936e+04 7.36506431e+04 1.83e-01 1.78e-02 4.43e-05 656s
    45 7.33703904e+04 7.35517820e+04 5.72e-04 9.42e-03 1.92e-05 658s
    46 7.34191286e+04 7.34356640e+04 7.25e-05 4.11e-04 1.76e-06 662s
    47 7.34259799e+04 7.34288957e+04 1.12e-05 7.14e-05 3.09e-07 664s
    48 7.34271084e+04 7.34273451e+04 9.33e-07 4.46e-06 2.51e-08 667s
    49 7.34272028e+04 7.34272189e+04 1.23e-07 3.97e-08 1.72e-09 669s
    50 7.34272172e+04 7.34272173e+04 1.89e-09 2.79e-09 5.72e-12 673s

    Barrier solved model in 50 iterations and 672.64 seconds
    Optimal objective 7.34272172e+04


    Root crossover log...

    155401 DPushes remaining with DInf 0.0000000e+00 676s
    11671 DPushes remaining with DInf 0.0000000e+00 680s
    7356 DPushes remaining with DInf 0.0000000e+00 685s
    1917 DPushes remaining with DInf 0.0000000e+00 690s
    0 DPushes remaining with DInf 3.9825782e-13 692s

    1335647 PPushes remaining with PInf 0.0000000e+00 693s
    631839 PPushes remaining with PInf 0.0000000e+00 696s
    339201 PPushes remaining with PInf 0.0000000e+00 701s
    215004 PPushes remaining with PInf 0.0000000e+00 706s
    153653 PPushes remaining with PInf 0.0000000e+00 711s
    128125 PPushes remaining with PInf 0.0000000e+00 715s
    114185 PPushes remaining with PInf 0.0000000e+00 721s
    7101 PPushes remaining with PInf 0.0000000e+00 726s
    0 PPushes remaining with PInf 0.0000000e+00 731s

    Push phase complete: Pinf 0.0000000e+00, Dinf 3.6398055e-13 731s


    Root simplex log...

    Iteration Objective Primal Inf. Dual Inf. Time
    1353769 7.3427217e+04 0.000000e+00 0.000000e+00 733s
    1353769 7.3427217e+04 0.000000e+00 0.000000e+00 737s
    Concurrent spin time: 0.07s

    Solved with barrier

    Root relaxation: objective 7.342722e+04, 1353769 iterations, 314.26 seconds
    Total elapsed time = 845.61s
    Total elapsed time = 888.56s
    Total elapsed time = 913.84s
    Total elapsed time = 928.64s

    Nodes | Current Node | Objective Bounds | Work
    Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time

    0 0 73427.2172 0 528166 62798.0000 73427.2172 16.9% - 942s
    H 0 0 66479.000000 73427.2172 10.5% - 5060s
    0 0 73260.6796 0 21377 66479.0000 73260.6796 10.2% - 5360s
    H 0 0 66519.000000 73260.6796 10.1% - 5579s
    0 0 69239.0000 0 379 66519.0000 69239.0000 4.09% - 5590s
    H 0 0 68888.000000 69239.0000 0.51% - 5591s
    0 0 69230.4395 0 1454 68888.0000 69230.4395 0.50% - 5594s
    H 0 0 69080.000000 69230.4395 0.22% - 5599s
    0 0 69227.2659 0 1593 69080.0000 69227.2659 0.21% - 5600s
    0 0 69226.8373 0 1434 69080.0000 69226.8373 0.21% - 5601s
    0 0 69226.8373 0 1430 69080.0000 69226.8373 0.21% - 5601s
    0 0 69210.0000 0 1814 69080.0000 69210.0000 0.19% - 5606s
    H 0 0 69153.000000 69210.0000 0.08% - 5608s
    0 0 69209.7273 0 1994 69153.0000 69209.7273 0.08% - 5609s
    0 0 69209.6000 0 2602 69153.0000 69209.6000 0.08% - 5611s
    0 0 69209.6000 0 2589 69153.0000 69209.6000 0.08% - 5612s
    0 0 69207.0000 0 2928 69153.0000 69207.0000 0.08% - 5638s
    H 0 0 69185.000000 69207.0000 0.03% - 5640s
    0 0 69205.0435 0 2963 69185.0000 69205.0435 0.03% - 5642s
    0 0 69204.4444 0 2840 69185.0000 69204.4444 0.03% - 5643s
    0 0 69204.4444 0 2734 69185.0000 69204.4444 0.03% - 5644s
    0 0 69204.0000 0 3016 69185.0000 69204.0000 0.03% - 5668s
    0 0 69204.0000 0 2867 69185.0000 69204.0000 0.03% - 5671s
    0 0 69204.0000 0 2759 69185.0000 69204.0000 0.03% - 5696s
    H 0 0 69188.000000 69204.0000 0.02% - 5697s
    0 0 69204.0000 0 3023 69188.0000 69204.0000 0.02% - 5700s
    0 0 69203.7500 0 61 69188.0000 69203.7500 0.02% - 5731s
    0 0 69203.7500 0 91 69188.0000 69203.7500 0.02% - 5733s
    0 0 69203.7500 0 22 69188.0000 69203.7500 0.02% - 5758s
    H 0 0 69203.000000 69203.7500 0.00% - 5759s

    Cutting planes:
    Gomory: 27
    Cover: 331
    Implied bound: 1188
    Clique: 39
    MIR: 282
    StrongCG: 114
    Flow cover: 548
    GUB cover: 1
    Zero half: 213

    Explored 1 nodes (2017641 simplex iterations) in 5763.98 seconds
    Thread count was 32 (of 40 available processors)

    Solution count 10: 69203 69188 69185 ... 62798

    Optimal solution found (tolerance 1.00e-04)
    Best objective 6.920300000000e+04, best bound 6.920300000000e+04, gap 0.0000%
    First model run time is 96.0964 minutes
    $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
    the real time for solving first model based on minutes is:
    152.8601791938146
    $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
    start second model
    Changed value of parameter MIPFocus to 2
    Prev: 0 Min: 0 Max: 3 Default: 0
    Changed value of parameter Cuts to 2
    Prev: -1 Min: -1 Max: 3 Default: -1
    Optimize a model with 36507928 rows, 36700601 columns and 47471207 nonzeros
    Model has 492693 quadratic constraints
    Variable types: 36379 continuous, 36664222 integer (36655752 binary)
    Coefficient statistics:
    Matrix range [6e-04, 1e+02]
    QMatrix range [2e-04, 1e+02]
    QLMatrix range [1e-03, 3e+01]
    Objective range [1e+00, 2e+01]
    Bounds range [1e+00, 1e+02]
    RHS range [1e+00, 5e+04]
    QRHS range [1e+00, 6e+04]

    Loaded MIP start with objective 69203 (75.69s)
    MIP start did not produce a new incumbent solution
    Processed MIP start in 80.56 seconds

    Presolve removed 875 rows and 866 columns (presolve time = 20s) ...
    Presolve removed 35741421 rows and 9275 columns (presolve time = 24s) ...
    Presolve removed 35741421 rows and 9275 columns (presolve time = 26s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 38s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 41s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 46s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 51s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 58s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 61s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 66s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 72s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 75s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 81s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 88s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 90s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 95s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 102s) ...
    Presolve removed 35742287 rows and 14684 columns (presolve time = 107s) ...
    Presolve removed 35743400 rows and 15797 columns (presolve time = 111s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 115s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 120s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 125s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 130s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 135s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 140s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 145s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 150s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 155s) ...
    Presolve removed 35743833 rows and 15797 columns (presolve time = 160s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 167s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 170s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 175s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 180s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 185s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 190s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 195s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 200s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 205s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 210s) ...
    Presolve removed 35752743 rows and 35608505 columns (presolve time = 215s) ...
    Presolve removed 35764131 rows and 35617702 columns (presolve time = 220s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 225s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 230s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 235s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 240s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 245s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 250s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 255s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 260s) ...
    Presolve removed 35764132 rows and 35617702 columns (presolve time = 265s) ...
    Presolve removed 35764951 rows and 35628830 columns (presolve time = 271s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 275s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 280s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 285s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 290s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 295s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 300s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 305s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 310s) ...
    Presolve removed 35764985 rows and 35628830 columns (presolve time = 315s) ...
    Presolve removed 35766610 rows and 35630455 columns (presolve time = 329s) ...
    Presolve removed 35766610 rows and 35630455 columns (presolve time = 340s) ...
    Presolve removed 35769047 rows and 35632892 columns (presolve time = 398s) ...
    Presolve removed 35767422 rows and 35631267 columns
    Presolve time: 397.76s
    Presolved: 4400594 rows, 4130859 columns, 15753610 nonzeros
    Variable types: 245080 continuous, 3885779 integer (3749569 binary)

    Deterministic concurrent LP optimizer: primal simplex, dual simplex, and barrier
    Showing barrier log only...

    Presolve removed 258210 rows and 250000 columns (presolve time = 6s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 10s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 15s) ...
    Presolve removed 1031515 rows and 1023305 columns (presolve time = 20s) ...
    Presolve removed 1031899 rows and 1023305 columns (presolve time = 25s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 30s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 35s) ...
    Presolve removed 1053039 rows and 1028896 columns (presolve time = 40s) ...
    Presolve removed 1059965 rows and 1028953 columns (presolve time = 45s) ...
    Presolve removed 1059965 rows and 1028953 columns
    Presolved: 3340629 rows, 3101906 columns, 13492070 nonzeros

    Root barrier log...

    Ordering time: 2.83s

    Barrier statistics:
    Dense cols : 1089
    AA' NZ : 8.155e+07
    Factor NZ : 1.409e+08 (roughly 4.0 GBytes of memory)
    Factor Ops : 4.754e+10 (roughly 1 second per iteration)
    Threads : 30

    Objective Residual
    Iter Primal Dual Primal Dual Compl Time
    0 5.91211808e+06 4.06997484e+07 2.08e+06 2.85e+00 3.70e+03 568s
    1 2.39250820e+06 7.25979098e+07 8.46e+05 8.89e+02 1.53e+03 570s
    2 5.10436363e+05 9.99254981e+07 1.63e+05 3.49e+03 3.20e+02 574s
    3 3.63649267e+05 9.38097546e+07 1.09e+05 4.30e+03 2.16e+02 578s
    4 2.75471823e+05 8.82589379e+07 7.70e+04 2.36e+03 1.53e+02 581s
    5 1.35387071e+05 8.20943416e+07 2.59e+04 3.21e+03 5.60e+01 583s
    6 9.60053838e+04 7.20754516e+07 1.14e+04 2.02e+03 2.70e+01 586s
    7 8.56810502e+04 5.84868343e+07 7.59e+03 1.12e+03 1.73e+01 590s
    8 7.81227897e+04 4.21162370e+07 4.82e+03 3.62e+02 9.97e+00 593s
    9 7.29613956e+04 2.47877733e+07 2.95e+03 1.28e+02 4.82e+00 598s
    10 6.76408931e+04 1.29595078e+07 1.01e+03 1.38e+02 1.80e+00 602s
    11 6.64601220e+04 6.48358183e+06 5.51e+02 7.46e+01 8.15e-01 605s
    12 6.61487666e+04 4.03272544e+06 4.14e+02 7.85e+01 4.87e-01 609s
    13 6.58661046e+04 2.56191353e+06 2.75e+02 2.16e+02 2.94e-01 614s
    14 6.56926278e+04 1.80500292e+06 1.85e+02 1.44e+02 1.98e-01 620s
    15 6.56121811e+04 1.32792631e+06 1.27e+02 1.05e+02 1.41e-01 625s
    16 6.56112523e+04 9.94820789e+05 1.01e+02 9.45e+01 1.03e-01 629s
    17 6.57047573e+04 8.68189300e+05 7.91e+01 8.10e+01 8.78e-02 632s
    18 6.58154019e+04 7.24737482e+05 6.12e+01 6.57e+01 7.15e-02 638s
    19 6.59973189e+04 4.07080792e+05 4.44e+01 3.31e+01 3.68e-02 643s
    20 6.62984219e+04 2.83787898e+05 2.86e+01 2.01e+01 2.33e-02 648s
    21 6.64503712e+04 2.56604276e+05 2.51e+01 1.76e+01 2.03e-02 653s
    22 6.68399598e+04 2.00471751e+05 2.03e+01 1.23e+01 1.42e-02 659s
    23 6.72451793e+04 1.62015766e+05 1.67e+01 8.61e+00 1.01e-02 665s
    24 6.75643734e+04 1.34165692e+05 1.46e+01 5.93e+00 7.08e-03 671s
    25 6.81522793e+04 1.16758163e+05 1.15e+01 4.25e+00 5.16e-03 676s
    26 6.86966328e+04 1.07942242e+05 9.38e+00 3.38e+00 4.16e-03 680s
    27 6.91034036e+04 9.93734350e+04 8.15e+00 2.54e+00 3.21e-03 684s
    28 6.94032174e+04 9.33113010e+04 7.36e+00 1.95e+00 2.54e-03 687s
    29 6.99843487e+04 8.80145317e+04 5.97e+00 1.43e+00 1.91e-03 689s
    30 7.03200308e+04 8.41051912e+04 5.25e+00 1.04e+00 1.46e-03 692s
    31 7.05807625e+04 8.20822630e+04 4.67e+00 8.42e-01 1.22e-03 695s
    32 7.12855300e+04 7.91503036e+04 3.39e+00 5.30e-01 8.34e-04 698s
    33 7.17162590e+04 7.64538614e+04 2.63e+00 2.77e-01 5.03e-04 702s
    34 7.21667217e+04 7.53720810e+04 1.89e+00 1.72e-01 3.40e-04 705s
    35 7.22772419e+04 7.50523019e+04 1.71e+00 1.42e-01 2.95e-04 708s
    36 7.23600398e+04 7.49921869e+04 1.58e+00 1.36e-01 2.79e-04 710s
    37 7.24142602e+04 7.49110885e+04 1.49e+00 1.29e-01 2.65e-04 712s
    38 7.25909243e+04 7.47088698e+04 1.23e+00 1.10e-01 2.25e-04 716s
    39 7.26499596e+04 7.45337280e+04 1.13e+00 9.43e-02 2.00e-04 718s
    40 7.27527302e+04 7.44063412e+04 9.80e-01 8.32e-02 1.76e-04 721s
    41 7.28321472e+04 7.42486010e+04 8.54e-01 6.93e-02 1.50e-04 725s
    42 7.28852776e+04 7.39519459e+04 7.73e-01 4.39e-02 1.13e-04 729s
    43 7.29887921e+04 7.38487422e+04 5.97e-01 3.45e-02 9.15e-05 731s
    44 7.32336936e+04 7.36506431e+04 1.83e-01 1.78e-02 4.43e-05 733s
    45 7.33703904e+04 7.35517820e+04 5.72e-04 9.42e-03 1.92e-05 736s
    46 7.34191286e+04 7.34356640e+04 7.25e-05 4.11e-04 1.76e-06 739s
    47 7.34259799e+04 7.34288957e+04 1.12e-05 7.14e-05 3.09e-07 741s
    48 7.34271084e+04 7.34273451e+04 9.33e-07 4.46e-06 2.51e-08 744s
    49 7.34272028e+04 7.34272189e+04 1.23e-07 3.97e-08 1.72e-09 747s
    50 7.34272172e+04 7.34272173e+04 1.89e-09 2.79e-09 5.72e-12 750s

    Barrier solved model in 50 iterations and 749.96 seconds
    Optimal objective 7.34272172e+04


    Root crossover log...

    155401 DPushes remaining with DInf 0.0000000e+00 753s
    13396 DPushes remaining with DInf 0.0000000e+00 755s
    9082 DPushes remaining with DInf 0.0000000e+00 760s
    3643 DPushes remaining with DInf 0.0000000e+00 766s
    0 DPushes remaining with DInf 0.0000000e+00 770s

    1335647 PPushes remaining with PInf 0.0000000e+00 771s
    469946 PPushes remaining with PInf 0.0000000e+00 776s
    279252 PPushes remaining with PInf 0.0000000e+00 781s
    185637 PPushes remaining with PInf 0.0000000e+00 786s
    140636 PPushes remaining with PInf 0.0000000e+00 790s
    122732 PPushes remaining with PInf 0.0000000e+00 795s
    51230 PPushes remaining with PInf 0.0000000e+00 800s
    3834 PPushes remaining with PInf 0.0000000e+00 806s
    0 PPushes remaining with PInf 0.0000000e+00 809s

    Push phase complete: Pinf 0.0000000e+00, Dinf 3.6398055e-13 809s


    Root simplex log...

    Iteration Objective Primal Inf. Dual Inf. Time
    1353769 7.3427217e+04 0.000000e+00 0.000000e+00 811s
    1353769 7.3427217e+04 0.000000e+00 0.000000e+00 815s
    Concurrent spin time: 0.02s

    Solved with barrier

    Root relaxation: objective 7.342722e+04, 1353769 iterations, 314.73 seconds
    Total elapsed time = 925.17s
    Total elapsed time = 967.70s
    Total elapsed time = 993.02s
    Total elapsed time = 1008.49s

    Nodes | Current Node | Objective Bounds | Work
    Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time

    0 0 73427.2172 0 528166 69203.0000 73427.2172 6.10% - 1022s
    0 0 73260.6796 0 19050 69203.0000 73260.6796 5.86% - 5434s
    0 0 69239.0000 0 427 69203.0000 69239.0000 0.05% - 5616s
    0 0 69223.0000 0 1102 69203.0000 69223.0000 0.03% - 5620s
    0 0 69217.3492 0 1638 69203.0000 69217.3492 0.02% - 5625s
    0 0 69203.0000 0 2215 69203.0000 69203.0000 0.00% - 5627s

    Cutting planes:
    Gomory: 31
    Cover: 85
    Implied bound: 180
    MIR: 127
    StrongCG: 66
    Flow cover: 194
    Zero half: 50

    Explored 1 nodes (1889803 simplex iterations) in 5630.62 seconds
    Thread count was 32 (of 40 available processors)

    Solution count 2: 69203 69203

    Optimal solution found (tolerance 1.00e-04)
    Best objective 6.920300000000e+04, best bound 6.920300000000e+04, gap 0.0000%
    Model run time for the model with optimal initial solution is 93.8731 minutes
    $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
    the real time for solving second model (with optimal initial solution) based on minutes is:
    149.74188153346378
    $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

    0
    Comment actions Permalink
  • Ting Liang

    Hi, Monir,

    Excuse me.

    Can I ask how to give MIP a new start? Has your long solving time problem been coped with? Can the MIPgap be set as 5%? I now encountered the same problem, the optimal solution cannot be obtained after long long term solving.

    Thanks.

     

    Best regards

    Ting, Liang

    0
    Comment actions Permalink
  • Wu Hao

    I also have the similar issue.

    I am solving a max MIP problem with MIPStart, where my logout file for heuristic/start solution generation is:


    Gurobi 9.0.2 (win64) logging started Tue Jul 7 05:16:49 2020

    Changed value of parameter LogFile to test_log_10_heu
    Prev: Default:
    Changed value of parameter LogToConsole to 0
    Prev: 1 Min: 0 Max: 1 Default: 1
    Gurobi Optimizer version 9.0.2 build v9.0.2rc0 (win64)
    Optimize a model with 1339 rows, 311 columns and 3199 nonzeros
    Model fingerprint: 0xa14c6391
    Model has 180 quadratic objective terms
    Model has 10 quadratic constraints
    Coefficient statistics:
    Matrix range [1e+00, 3e+02]
    QMatrix range [1e+00, 1e+00]
    QLMatrix range [1e+00, 1e+00]
    Objective range [1e+00, 1e+00]
    QObjective range [5e+00, 4e+03]
    Bounds range [1e+00, 1e+00]
    RHS range [1e-14, 1e+00]
    Presolve removed 1230 rows and 119 columns

    Continuous model is non-convex -- solving as a MIP.

    Found heuristic solution: objective -0.0000000
    Presolve removed 959 rows and 119 columns
    Presolve time: 0.03s
    Presolved: 725 rows, 365 columns, 1937 nonzeros
    Presolved model has 10 quadratic constraint(s)
    Presolved model has 172 bilinear constraint(s)
    Found heuristic solution: objective 0.0000000
    Variable types: 365 continuous, 0 integer (0 binary)

    Root relaxation: objective 2.540823e+03, 390 iterations, 0.00 seconds

    Nodes | Current Node | Objective Bounds | Work
    Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time

    0 0 2540.82256 0 26 0.00000 2540.82256 - - 0s
    H 0 0 1509.4852428 2540.82256 68.3% - 0s
    0 0 2079.07566 0 40 1509.48524 2079.07566 37.7% - 0s
    H 0 0 1550.0431927 2079.07566 34.1% - 0s
    0 0 2001.44280 0 55 1550.04319 2001.44280 29.1% - 0s
    0 0 2001.37735 0 55 1550.04319 2001.37735 29.1% - 0s
    0 0 1976.85251 0 77 1550.04319 1976.85251 27.5% - 0s
    0 0 1948.88692 0 74 1550.04319 1948.88692 25.7% - 0s
    0 0 1945.68252 0 76 1550.04319 1945.68252 25.5% - 0s
    0 0 1938.66927 0 102 1550.04319 1938.66927 25.1% - 0s
    0 0 1938.64076 0 104 1550.04319 1938.64076 25.1% - 0s
    0 0 1936.46132 0 94 1550.04319 1936.46132 24.9% - 0s
    0 0 1936.34222 0 105 1550.04319 1936.34222 24.9% - 0s
    0 0 1935.50957 0 105 1550.04319 1935.50957 24.9% - 0s
    0 0 1935.50399 0 106 1550.04319 1935.50399 24.9% - 0s
    0 0 1935.08157 0 106 1550.04319 1935.08157 24.8% - 0s
    0 2 1935.08157 0 106 1550.04319 1935.08157 24.8% - 0s
    H 423 365 1574.9129922 1864.43860 18.4% 13.6 0s
    H 436 311 1585.0680652 1864.43860 17.6% 13.5 0s
    H 1195 396 1690.2470492 1720.52905 1.79% 21.1 2s
    3402 453 1695.69309 28 31 1690.24705 1704.76997 0.86% 28.9 5s
    7871 702 cutoff 33 1690.24705 1698.11825 0.47% 29.3 10s
    *11818 617 44 1690.2505813 1694.90813 0.28% 27.3 14s
    *11828 617 44 1690.2506760 1694.90813 0.28% 27.3 14s
    12887 493 1690.75431 28 58 1690.25068 1694.04991 0.22% 26.7 15s

    Cutting planes:
    RLT: 120

    Explored 15664 nodes (394114 simplex iterations) in 18.52 seconds
    Thread count was 4 (of 4 available processors)

    Solution count 9: 1690.25 1690.25 1690.25 ... -0

    Optimal solution found (tolerance 1.00e-04)
    Warning: max constraint violation (1.5623e-05) exceeds tolerance
    Best objective 1.690247205714e+03, best bound 1.690250676025e+03, gap 0.0002%

    And the logout file for which I apply variables value derived from the above model looks like below:

    Changed value of parameter TuneOutput to 3
    Prev: 2 Min: 0 Max: 3 Default: 2

    Solving model using baseline parameter set with TimeLimit=3600s

    Solving with random seed #1 ...
    Optimize a model with 331 rows, 321 columns and 1591 nonzeros
    Model fingerprint: 0xb7409f8d
    Model has 180 quadratic objective terms
    Model has 1010 quadratic constraints
    Variable types: 311 continuous, 10 integer (10 binary)
    Coefficient statistics:
    Matrix range [1e+00, 3e+02]
    QMatrix range [1e+00, 1e+00]
    QLMatrix range [1e+00, 1e+00]
    Objective range [1e+00, 1e+00]
    QObjective range [5e+00, 4e+03]
    Bounds range [1e+00, 1e+00]
    RHS range [0e+00, 0e+00]
    QRHS range [1e+00, 1e+00]

    User MIP start did not produce a new incumbent solution

    Found heuristic solution: objective -0.0000000
    Presolve removed 121 rows and 101 columns
    Presolve time: 0.11s
    Presolved: 611 rows, 422 columns, 1911 nonzeros
    Presolved model has 900 quadratic constraint(s)
    Presolved model has 190 bilinear constraint(s)
    Found heuristic solution: objective 0.0000000
    Variable types: 412 continuous, 10 integer (10 binary)

    Root relaxation: objective 2.576555e+03, 374 iterations, 0.02 seconds

    Nodes | Current Node | Objective Bounds | Work
    Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time

    0 0 2576.55531 0 38 0.00000 2576.55531 - - 0s
    0 0 2185.29566 0 68 0.00000 2185.29566 - - 0s
    0 0 2104.35344 0 83 0.00000 2104.35344 - - 0s
    0 0 2014.55289 0 46 0.00000 2014.55289 - - 0s
    0 0 1987.20797 0 62 0.00000 1987.20797 - - 0s
    H 0 0 640.1187624 1987.20797 210% - 0s
    H 0 0 1019.5453139 1987.20797 94.9% - 0s
    0 0 1987.00806 0 62 1019.54531 1987.00806 94.9% - 0s
    0 0 1983.81579 0 59 1019.54531 1983.81579 94.6% - 0s
    0 2 1983.81579 0 59 1019.54531 1983.81579 94.6% - 0s
    1462 1573 1765.57290 371 32 1019.54531 1935.08714 89.8% 8.5 5s
    H 1582 1500 1021.7508718 1935.08714 89.4% 8.1 5s
    H 1582 1425 1445.9993931 1935.08714 33.8% 8.1 5s
    H 1582 1354 1601.2367780 1935.08714 20.8% 8.1 5s
    H 1582 1286 1633.7112882 1935.08714 18.4% 8.1 5s
    2765 2099 cutoff 120 1633.71129 1935.08714 18.4% 13.1 10s
    4806 3766 1712.57676 461 10 1633.71129 1935.08714 18.4% 10.4 15s
    7167 5616 1720.72853 137 15 1633.71129 1914.30822 17.2% 12.8 20s
    9528 7940 1689.70364 330 13 1633.71129 1914.30822 17.2% 11.1 25s
    12783 10712 1687.57938 543 10 1633.71129 1914.30822 17.2% 10.0 30s
    15200 12769 1653.86924 676 17 1633.71129 1909.17431 16.9% 10.6 35s
    16948 14047 1767.90510 69 39 1633.71129 1886.10530 15.4% 11.7 40s
    18332 15004 1795.38778 24 35 1633.71129 1883.63627 15.3% 11.8 45s
    19241 15775 1646.23756 70 32 1633.71129 1879.99999 15.1% 12.5 50s
    21462 17635 1781.49045 73 28 1633.71129 1877.71236 14.9% 12.1 55s
    23057 19165 1816.20040 140 14 1633.71129 1876.44898 14.9% 11.8 60s
    25338 21158 1679.00030 54 35 1633.71129 1875.81669 14.8% 11.5 65s
    27135 22444 1820.67106 40 62 1633.71129 1874.35245 14.7% 11.5 70s
    28784 23982 1696.91663 195 27 1633.71129 1874.35245 14.7% 11.3 75s
    31220 26585 1685.90592 429 11 1633.71129 1874.35245 14.7% 10.7 80s
    33642 28727 1752.57123 96 35 1633.71129 1872.79449 14.6% 10.4 85s
    35282 30240 1774.94550 67 21 1633.71129 1872.17256 14.6% 10.1 90s
    39199 33723 1777.63129 61 24 1633.71129 1871.68823 14.6% 9.4 95s
    41150 35486 1739.58555 225 9 1633.71129 1871.64146 14.6% 9.4 100s
    42675 37180 1692.24856 173 37 1633.71129 1870.50861 14.5% 9.6 105s
    45377 39182 1776.40750 132 20 1633.71129 1869.97908 14.5% 9.4 110s
    49219 42954 1769.14643 492 10 1633.71129 1869.97908 14.5% 8.9 115s
    51203 44834 1662.96231 669 8 1633.71129 1869.26993 14.4% 8.8 120s
    54076 47545 cutoff 574 1633.71129 1868.91370 14.4% 8.5 125s
    57344 50516 1772.53146 177 19 1633.71129 1868.57867 14.4% 8.4 130s
    61003 54026 1732.86344 598 8 1633.71129 1868.57867 14.4% 8.2 135s
    64367 57055 1740.73627 303 10 1633.71129 1867.78778 14.3% 8.1 140s
    67087 59477 1828.57698 24 29 1633.71129 1867.71348 14.3% 8.3 145s
    68967 61108 1758.23704 68 30 1633.71129 1867.35581 14.3% 8.3 150s
    72661 64787 cutoff 162 1633.71129 1867.19909 14.3% 8.2 155s
    76180 67821 1799.24990 38 20 1633.71129 1866.76061 14.3% 8.1 160s
    78563 70280 1701.58423 402 9 1633.71129 1866.76061 14.3% 8.1 165s
    82085 73445 1739.90530 297 11 1633.71129 1865.99886 14.2% 8.0 170s
    84939 75886 1668.65248 512 9 1633.71129 1865.99886 14.2% 8.0 175s
    87559 78090 1709.09194 121 24 1633.71129 1865.34626 14.2% 8.1 180s
    89346 79876 1811.65642 37 19 1633.71129 1864.92713 14.2% 8.1 185s
    91641 82131 1734.21761 80 30 1633.71129 1864.79527 14.1% 8.0 190s
    95905 86328 1701.63634 137 40 1633.71129 1864.72456 14.1% 7.7 195s
    99458 89781 1687.34375 291 36 1633.71129 1864.72456 14.1% 7.6 200s
    102947 93028 1685.71960 453 25 1633.71129 1864.72456 14.1% 7.5 205s
    105948 95584 1786.82183 34 29 1633.71129 1864.41858 14.1% 7.4 210s
    108655 97955 1838.95990 25 36 1633.71129 1863.62730 14.1% 7.4 215s
    110580 99612 1769.22317 65 29 1633.71129 1863.41913 14.1% 7.4 220s
    113428 102084 1747.21467 198 31 1633.71129 1863.20731 14.0% 7.4 225s
    117235 105620 1682.88304 518 18 1633.71129 1863.20731 14.0% 7.2 230s
    119892 108241 cutoff 141 1633.71129 1862.10393 14.0% 7.2 235s
    122649 110669 1753.99260 143 20 1633.71129 1861.76886 14.0% 7.2 240s
    125435 113191 1701.01393 665 8 1633.71129 1861.76886 14.0% 7.2 245s
    129062 116492 1679.09839 122 29 1633.71129 1860.94958 13.9% 7.3 250s
    130692 117965 1796.40478 50 51 1633.71129 1860.51480 13.9% 7.3 255s
    133283 120003 1743.46977 46 34 1633.71129 1860.40445 13.9% 7.3 260s
    134794 121618 1657.71334 243 28 1633.71129 1860.40445 13.9% 7.3 265s
    136965 123183 cutoff 47 1633.71129 1859.53817 13.8% 7.3 270s
    139232 125423 1732.92046 143 12 1633.71129 1859.44777 13.8% 7.3 275s
    140593 126662 1729.29997 242 11 1633.71129 1859.44777 13.8% 7.3 280s
    144611 130358 1728.15269 447 10 1633.71129 1859.44777 13.8% 7.2 285s
    147814 133338 1634.70271 597 7 1633.71129 1858.94949 13.8% 7.1 290s
    151462 136537 1770.99395 32 55 1633.71129 1858.86391 13.8% 7.1 295s
    154064 138839 1677.51300 73 34 1633.71129 1858.57973 13.8% 7.2 300s
    156441 141137 1751.21197 400 10 1633.71129 1858.45370 13.8% 7.2 305s
    159772 144257 1802.37217 26 48 1633.71129 1858.28215 13.7% 7.2 310s
    162514 146332 1740.95145 236 19 1633.71129 1858.10750 13.7% 7.3 315s
    164234 147836 1737.41715 418 11 1633.71129 1858.10750 13.7% 7.3 320s
    166187 149547 1737.08980 567 10 1633.71129 1858.10750 13.7% 7.2 325s
    167342 150645 1737.05617 647 10 1633.71129 1858.10750 13.7% 7.2 330s
    168954 151856 1734.04818 682 9 1633.71129 1858.10750 13.7% 7.2 335s
    171003 153747 1700.96525 147 22 1633.71129 1857.45101 13.7% 7.2 340s
    174850 157610 1750.79468 189 19 1633.71129 1857.25051 13.7% 7.2 345s
    180293 162728 1746.12615 565 10 1633.71129 1857.25051 13.7% 7.0 350s
    183574 165565 1827.34695 22 21 1633.71129 1856.84725 13.7% 7.0 355s
    187488 169305 1744.52363 47 31 1633.71129 1856.81288 13.7% 7.0 360s
    189947 171382 1805.68852 22 58 1633.71129 1856.72226 13.7% 7.0 365s
    192081 173026 1647.88057 672 21 1633.71129 1856.63808 13.6% 7.1 370s
    194943 175483 1663.69756 393 28 1633.71129 1856.36194 13.6% 7.1 375s
    197082 177181 cutoff 48 1633.71129 1856.12049 13.6% 7.1 380s
    200341 179854 1675.73012 471 12 1633.71129 1856.04057 13.6% 7.1 385s
    202728 181562 1659.41875 468 9 1633.71129 1855.70176 13.6% 7.1 390s
    204411 183062 1637.49682 594 21 1633.71129 1855.70029 13.6% 7.1 395s
    205328 184002 1660.09213 168 31 1633.71129 1855.48774 13.6% 7.1 400s
    208328 186576 1721.04696 407 10 1633.71129 1855.45045 13.6% 7.1 405s
    211729 189463 1762.70634 136 12 1633.71129 1855.11138 13.6% 7.1 410s
    214284 191603 1752.10020 492 10 1633.71129 1855.11138 13.6% 7.0 415s
    216267 193430 1681.44625 649 7 1633.71129 1855.11138 13.6% 7.1 420s
    219964 196893 1742.59240 603 10 1633.71129 1854.83773 13.5% 7.0 425s
    223096 199220 1744.60201 69 58 1633.71129 1854.70493 13.5% 7.1 430s
    227207 203096 1675.44293 385 10 1633.71129 1854.70493 13.5% 7.0 435s
    230312 205684 1645.58308 96 32 1633.71129 1854.27442 13.5% 7.0 440s
    233542 208708 1810.38708 31 21 1633.71129 1854.17498 13.5% 7.0 445s
    235732 210486 1650.97945 278 29 1633.71129 1854.01993 13.5% 7.0 450s
    237051 211604 cutoff 46 1633.71129 1853.90549 13.5% 7.0 455s
    238036 212673 1704.35386 368 21 1633.71129 1853.87793 13.5% 7.0 460s
    239506 213961 1675.07695 243 9 1633.71129 1853.81999 13.5% 7.0 465s
    242558 217156 1711.87982 151 13 1633.71129 1853.81999 13.5% 7.0 470s
    245646 220196 1709.87347 234 17 1633.71129 1853.81999 13.5% 6.9 475s
    247312 221208 1709.28725 279 14 1633.71129 1853.81999 13.5% 6.9 480s
    248528 222389 1709.02575 313 12 1633.71129 1853.81999 13.5% 6.9 485s
    251260 225080 1708.89128 342 11 1633.71129 1853.81999 13.5% 6.9 490s
    253550 227196 1708.82351 361 11 1633.71129 1853.81999 13.5% 6.8 495s

     

    And it lasts until time limit 3600s was achieved. I am curious about the reason that the second problem has such statement while deriving initial objective value much less than the one I had in the first one, and is there anyway to improve such computational inefficiency? Thank you very much!

     

    Best,

    Wu

     

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