Barrier Method and Crossover in Large-Scale LP Solving
Ongoing
Hello,
I am currently working on solving a large-scale linear programming (LP) problem using the barrier method. In an effort to reduce the overall solve time, I have disabled the crossover step by setting Crossover to 0. However, I've encountered an issue where the model becomes infeasible with crossover disabled. Conversely, when I allow crossover (Crossover set to non-zero), the model solves successfully.
From my understanding, both approaches should theoretically yield the same optimal solution, but this does not seem to be the case here. Could someone please explain why this discrepancy might occur and suggest any strategies to ensure feasibility without the crossover step?
Below are the log outputs for both scenarios:
With Crossover Disabled (Infeasible):
开始求解...
Set parameter Username
Set parameter Method to value 2
Set parameter Crossover to value 0
Set parameter NodefileDir to value ""
Set parameter TuneTimeLimit to value 1e+100
Academic license - for non-commercial use only - expires 2024-11-02
Gurobi Optimizer version 10.0.3 build v10.0.3rc0 (win64)
CPU model: 13th Gen Intel(R) Core(TM) i7-13700K, instruction set [SSE2|AVX|AVX2]
Thread count: 16 physical cores, 24 logical processors, using up to 24 threads
Optimize a model with 4702180 rows, 2210651 columns and 19350520 nonzeros
Model fingerprint: 0x34eacf5d
Coefficient statistics:
Matrix range [2e-05, 1e+01]
Objective range [2e-03, 2e+02]
Bounds range [0e+00, 0e+00]
RHS range [2e-02, 8e+04]
Presolve removed 1017341 rows and 3083838 columns (presolve time = 5s) ...
Presolve removed 1022585 rows and 3117081 columns
Presolve time: 8.34s
Presolved: 1188066 rows, 1585099 columns, 11208382 nonzeros
Elapsed ordering time = 8s
Elapsed ordering time = 10s
Elapsed ordering time = 44s
Elapsed ordering time = 46s
Elapsed ordering time = 50s
Elapsed ordering time = 55s
Elapsed ordering time = 60s
Elapsed ordering time = 65s
Elapsed ordering time = 70s
Elapsed ordering time = 75s
Ordering time: 78.87s
Barrier statistics:
Dense cols : 53
Free vars : 185912
AA' NZ : 2.455e+07
Factor NZ : 1.298e+09 (roughly 12.0 GB of memory)
Factor Ops : 5.358e+12 (roughly 30 seconds per iteration)
Threads : 16
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.60479324e+11 7.57738388e+11 7.72e+06 1.07e+05 1.91e+08 180s
1 1.21109862e+11 6.73035539e+11 6.61e+06 8.97e+04 1.62e+08 236s
2 9.85913920e+10 6.11755544e+11 5.98e+06 7.33e+04 1.41e+08 269s
3 6.00163845e+10 5.98520307e+11 4.89e+06 6.80e+04 1.21e+08 302s
4 2.34511155e+10 5.77679856e+11 3.88e+06 5.86e+04 1.00e+08 336s
5 -1.90850823e+09 5.57508179e+11 3.17e+06 4.97e+04 8.34e+07 372s
6 -2.19233569e+10 5.34155809e+11 2.60e+06 4.16e+04 6.92e+07 407s
7 -3.67534570e+10 5.00345643e+11 2.16e+06 3.34e+04 5.69e+07 443s
8 -4.95099462e+10 4.56855334e+11 1.78e+06 2.72e+04 4.66e+07 479s
9 -5.82108313e+10 3.97186068e+11 1.49e+06 2.19e+04 3.85e+07 514s
10 -6.44665411e+10 3.42705528e+11 1.27e+06 1.79e+04 3.22e+07 548s
11 -7.27545037e+10 2.40387346e+11 9.30e+05 1.27e+04 2.34e+07 582s
12 -7.53034248e+10 2.09736840e+11 7.72e+05 1.12e+04 2.00e+07 615s
13 -7.60856146e+10 1.60178577e+11 6.74e+05 9.00e+03 1.68e+07 649s
14 -7.60401845e+10 1.41056929e+11 6.17e+05 8.16e+03 1.53e+07 683s
15 -7.57067626e+10 1.28633956e+11 5.92e+05 7.60e+03 1.45e+07 716s
16 -7.47529955e+10 9.14730833e+10 4.88e+05 5.73e+03 1.15e+07 751s
17 -7.18945856e+10 6.43040644e+10 3.80e+05 4.29e+03 8.80e+06 785s
18 -6.86699746e+10 4.56125301e+10 3.15e+05 3.18e+03 6.91e+06 819s
19 -6.31229438e+10 3.36333327e+10 2.33e+05 2.45e+03 5.23e+06 853s
20 -6.00223035e+10 2.46347749e+10 2.05e+05 1.87e+03 4.29e+06 887s
21 -5.47927599e+10 1.72725798e+10 1.67e+05 1.38e+03 3.33e+06 922s
22 -4.29241460e+10 8.66302916e+09 9.79e+04 7.48e+02 1.92e+06 956s
23 -2.61574653e+10 5.80406018e+09 3.70e+04 4.74e+02 9.99e+05 990s
24 -1.64676223e+10 2.98424168e+09 1.36e+04 2.04e+02 4.19e+05 1025s
25 -1.07898114e+10 1.85390484e+09 5.53e+03 9.61e+01 1.93e+05 1058s
26 -9.14884822e+09 1.48453617e+09 3.89e+03 6.44e+01 1.32e+05 1091s
27 -8.04149873e+09 1.26557127e+09 2.93e+03 4.73e+01 9.87e+04 1123s
28 -6.62108885e+09 1.07473746e+09 1.84e+03 3.37e+01 6.88e+04 1154s
29 -5.88496106e+09 9.59553175e+08 1.37e+03 2.64e+01 5.35e+04 1186s
30 -5.32811101e+09 8.08868430e+08 1.06e+03 1.78e+01 3.78e+04 1219s
31 -4.52824184e+09 6.75334272e+08 6.92e+02 1.16e+01 2.49e+04 1252s
32 -3.78002801e+09 5.59991718e+08 4.38e+02 7.43e+00 1.61e+04 1287s
33 -3.27772904e+09 5.07479469e+08 3.08e+02 5.90e+00 1.24e+04 1321s
34 -2.75320918e+09 4.67665758e+08 1.95e+02 4.84e+00 9.49e+03 1354s
35 -2.48648186e+09 4.23693691e+08 1.56e+02 3.82e+00 7.53e+03 1387s
36 -2.07333112e+09 3.50071569e+08 1.03e+02 2.32e+00 4.77e+03 1420s
37 -1.73920123e+09 3.09629795e+08 7.36e+01 1.68e+00 3.46e+03 1455s
38 -1.07171149e+09 2.71410582e+08 2.63e+01 1.18e+00 2.05e+03 1489s
39 -5.95799177e+08 1.87180615e+08 9.15e+00 5.06e-01 8.72e+02 1522s
40 -5.52061190e+08 1.71422611e+08 8.14e+00 4.41e-01 7.69e+02 1559s
41 -3.55090717e+08 1.05940983e+08 4.54e+00 1.76e-01 3.59e+02 1591s
42 -3.04999410e+08 1.01046506e+08 3.72e+00 1.62e-01 3.13e+02 1623s
43 -2.41672814e+08 9.00751476e+07 2.74e+00 1.32e-01 2.45e+02 1647s
44 -1.77069424e+08 7.90428134e+07 3.00e+00 1.04e-01 1.79e+02 1679s
45 -1.40634523e+08 7.35637170e+07 3.25e+00 9.04e-02 1.45e+02 1711s
46 -1.19217981e+08 6.84405074e+07 3.54e+00 7.84e-02 1.23e+02 1744s
47 -1.18419693e+08 6.83602727e+07 3.57e+00 7.83e-02 1.22e+02 1779s
48 -1.14217679e+08 6.64359973e+07 3.61e+00 7.41e-02 1.16e+02 1815s
49 -1.01845551e+08 6.24549825e+07 3.74e+00 6.58e-02 9.60e+01 1849s
50 -9.54955228e+07 6.16147096e+07 3.80e+00 6.39e-02 9.09e+01 1883s
51 -9.54939426e+07 6.16137470e+07 3.80e+00 6.39e-02 9.09e+01 1918s
52 -9.06379812e+07 5.94038963e+07 1.76e+00 4.86e-02 8.19e+01 1953s
53 -8.34584063e+07 5.76483782e+07 2.11e+00 4.55e-02 7.50e+01 1988s
54 -6.98606461e+07 5.40253872e+07 2.86e+00 3.93e-02 6.26e+01 2024s
55 -6.67227080e+07 5.24962051e+07 2.93e+00 3.68e-02 5.89e+01 2060s
56 -6.32371405e+07 5.11027030e+07 3.03e+00 3.45e-02 5.53e+01 2084s
57 -5.00961063e+07 4.72120456e+07 3.27e+00 2.82e-02 4.34e+01 2101s
58 -5.00222813e+07 4.71182613e+07 3.28e+00 2.81e-02 4.33e+01 2117s
59 -5.00222796e+07 4.71191007e+07 3.25e+00 2.81e-02 4.33e+01 2133s
60 -4.99200082e+07 4.69982942e+07 3.25e+00 2.80e-02 4.29e+01 2149s
61 -4.65120095e+07 4.60759070e+07 3.46e+00 2.65e-02 4.00e+01 2166s
62 -4.65112511e+07 4.60741662e+07 3.47e+00 2.65e-02 4.00e+01 2182s
63 -4.64499555e+07 4.60105962e+07 3.46e+00 2.64e-02 3.99e+01 2199s
64 -4.64194438e+07 4.59882097e+07 3.48e+00 2.64e-02 3.99e+01 2215s
65 -4.64028701e+07 4.59783571e+07 3.64e+00 2.64e-02 3.98e+01 2231s
66 -4.59390513e+07 4.53699518e+07 3.91e+00 2.54e-02 3.90e+01 2248s
67 -4.58880860e+07 4.53195317e+07 3.93e+00 2.53e-02 3.89e+01 2263s
68 -4.48145291e+07 4.50937121e+07 3.91e+00 2.50e-02 3.81e+01 2279s
69 -4.46707076e+07 4.49881063e+07 3.90e+00 2.48e-02 3.79e+01 2295s
70 -4.31958551e+07 4.47641925e+07 3.94e+00 2.45e-02 3.68e+01 2310s
71 -4.31922384e+07 4.47621720e+07 3.94e+00 2.45e-02 3.68e+01 2326s
Barrier performed 71 iterations in 2325.75 seconds (1642.99 work units)
Numerical trouble encountered
Model may be infeasible or unbounded. Consider using the
homogeneous algorithm (through parameter 'BarHomogeneous')
Hmm, something went wrong!
ans =
'Numerical problems (learn to debug) (GUROBI)'
With Crossover Enabled (Feasible):
开始求解...
Set parameter Username
Set parameter Method to value 2
Set parameter NodefileDir to value ""
Set parameter TuneTimeLimit to value 1e+100
Academic license - for non-commercial use only - expires 2024-11-02
Gurobi Optimizer version 10.0.3 build v10.0.3rc0 (win64)
CPU model: 13th Gen Intel(R) Core(TM) i7-13700K, instruction set [SSE2|AVX|AVX2]
Thread count: 16 physical cores, 24 logical processors, using up to 24 threads
Optimize a model with 4702180 rows, 2210651 columns and 19350520 nonzeros
Model fingerprint: 0x34eacf5d
Coefficient statistics:
Matrix range [2e-05, 1e+01]
Objective range [2e-03, 2e+02]
Bounds range [0e+00, 0e+00]
RHS range [2e-02, 8e+04]
Presolve removed 3193268 rows and 959826 columns
Presolve time: 4.68s
Presolved: 1508912 rows, 1250825 columns, 10884775 nonzeros
Elapsed ordering time = 5s
Elapsed ordering time = 10s
Ordering time: 24.53s
Barrier statistics:
Dense cols : 121
AA' NZ : 2.471e+07
Factor NZ : 3.092e+08 (roughly 3.6 GB of memory)
Factor Ops : 4.505e+11 (roughly 1 second per iteration)
Threads : 16
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.19314977e+11 -1.66916072e+12 6.81e+09 2.72e+00 2.91e+08 36s
1 1.02550801e+11 -1.48066755e+12 5.20e+09 9.00e+01 2.24e+08 40s
2 9.81491294e+10 -1.33085298e+12 4.91e+09 6.94e+01 1.97e+08 43s
3 6.87460931e+10 -1.10221545e+12 3.42e+09 4.56e+01 1.34e+08 47s
4 4.99042583e+10 -8.36297386e+11 2.16e+09 2.42e+01 7.96e+07 50s
5 4.00117962e+10 -6.74457023e+11 1.37e+09 1.57e+01 5.16e+07 54s
6 3.53703074e+10 -5.85276937e+11 9.50e+08 1.25e+01 3.86e+07 56s
7 3.15729817e+10 -4.94705942e+11 6.48e+08 9.70e+00 2.83e+07 58s
8 2.81519644e+10 -3.63653095e+11 4.73e+08 6.00e+00 1.90e+07 60s
9 2.50878640e+10 -3.04510934e+11 3.48e+08 4.63e+00 1.44e+07 62s
10 2.03635362e+10 -1.95518641e+11 2.14e+08 2.37e+00 8.32e+06 65s
11 1.51874546e+10 -1.28614880e+11 1.18e+08 1.27e+00 4.64e+06 67s
12 1.32183449e+10 -1.08223468e+11 8.70e+07 1.02e+00 3.53e+06 70s
13 1.07836655e+10 -7.26200054e+10 5.40e+07 5.84e-01 2.17e+06 72s
14 9.45472448e+09 -4.62526217e+10 3.84e+07 3.09e-01 1.44e+06 73s
15 7.76787769e+09 -2.77971353e+10 2.15e+07 1.38e-01 7.81e+05 75s
16 6.49920483e+09 -2.04627453e+10 1.29e+07 8.44e-02 4.75e+05 77s
17 5.43810509e+09 -1.57334965e+10 7.73e+06 5.55e-02 2.92e+05 79s
18 4.68985201e+09 -1.19151358e+10 5.09e+06 3.59e-02 1.94e+05 80s
19 3.90548672e+09 -9.11438776e+09 3.07e+06 2.37e-02 1.20e+05 82s
20 3.50362094e+09 -6.96238559e+09 2.33e+06 1.57e-02 8.97e+04 84s
21 2.72366707e+09 -5.21068203e+09 1.19e+06 9.72e-03 4.84e+04 85s
22 1.83493612e+09 -3.78252287e+09 4.15e+05 5.73e-03 1.95e+04 87s
23 1.26339461e+09 -2.39620594e+09 1.32e+05 2.57e-03 7.24e+03 89s
24 7.85350677e+08 -1.16820612e+09 3.48e+04 6.59e-04 2.12e+03 91s
25 4.64138943e+08 -6.93675709e+08 1.51e+04 3.12e-04 9.72e+02 92s
26 2.80492971e+08 -4.18443510e+08 7.95e+03 1.52e-04 5.05e+02 94s
27 1.73008894e+08 -2.37990163e+08 4.18e+03 7.05e-05 2.61e+02 96s
28 6.08017596e+07 -1.28795307e+08 1.03e+03 2.77e-05 9.68e+01 98s
29 2.45274479e+07 -3.65677584e+07 3.10e+02 2.78e-06 2.76e+01 100s
30 1.18407207e+07 -3.11402436e+07 1.25e+02 2.33e-06 1.86e+01 102s
31 1.09786495e+07 -2.04964917e+07 1.14e+02 1.50e-06 1.35e+01 104s
32 9.48210889e+06 -1.50112608e+07 9.55e+01 1.07e-06 1.05e+01 106s
33 6.03487751e+06 -6.70873772e+06 5.54e+01 4.55e-07 5.36e+00 107s
34 3.33135324e+06 -4.34685581e+06 2.80e+01 2.71e-07 3.20e+00 110s
35 2.37134931e+06 -3.08418196e+06 1.92e+01 1.83e-07 2.26e+00 112s
36 1.74840442e+06 -2.22033694e+06 1.36e+01 1.27e-07 1.64e+00 114s
37 1.46735205e+06 -1.81525728e+06 1.13e+01 1.01e-07 1.35e+00 116s
38 1.27257508e+06 -1.76346260e+06 9.74e+00 9.76e-08 1.25e+00 117s
39 1.00110700e+06 -1.42670948e+06 7.22e+00 7.71e-08 9.94e-01 119s
40 8.53592665e+05 -1.02226808e+06 5.74e+00 5.30e-08 7.64e-01 122s
41 6.51302093e+05 -7.40271638e+05 4.02e+00 3.71e-08 5.63e-01 124s
42 5.55486191e+05 -5.22943479e+05 3.22e+00 2.55e-08 4.34e-01 126s
43 4.62668316e+05 -3.41621483e+05 2.46e+00 1.64e-08 3.21e-01 129s
44 4.02850471e+05 -2.44074810e+05 1.97e+00 1.17e-08 2.56e-01 131s
45 3.46795637e+05 -1.66299853e+05 1.51e+00 8.92e-09 2.01e-01 134s
46 3.05516714e+05 -1.07764797e+05 1.17e+00 6.96e-09 1.60e-01 136s
47 2.69513516e+05 -5.49496663e+04 8.72e-01 5.19e-09 1.23e-01 139s
48 2.35852379e+05 -2.85665721e+04 5.96e-01 4.32e-09 9.85e-02 141s
49 2.10562097e+05 -5.38302207e+03 3.68e-01 3.55e-09 7.87e-02 143s
50 2.03116696e+05 2.01985747e+04 2.76e-01 2.70e-09 6.51e-02 146s
51 1.85092432e+05 2.59612305e+04 1.65e-01 2.47e-09 5.55e-02 148s
52 1.71212023e+05 3.91529251e+04 1.33e-01 1.96e-09 4.45e-02 150s
53 1.59776647e+05 4.30357612e+04 1.07e-01 1.78e-09 3.84e-02 153s
54 1.54340202e+05 5.17111820e+04 9.60e-02 1.41e-09 3.26e-02 155s
55 1.43966188e+05 5.61743895e+04 7.44e-02 1.22e-09 2.67e-02 157s
56 1.38008118e+05 6.12181830e+04 6.27e-02 9.96e-10 2.23e-02 160s
57 1.31276151e+05 6.54110521e+04 4.98e-02 8.07e-10 1.80e-02 162s
58 1.28690952e+05 6.79088400e+04 4.56e-02 6.90e-10 1.60e-02 164s
59 1.25885734e+05 7.08318487e+04 4.05e-02 5.49e-10 1.37e-02 167s
60 1.20408897e+05 7.28100155e+04 3.10e-02 4.52e-10 1.08e-02 169s
61 1.17695738e+05 7.55139578e+04 2.65e-02 4.57e-10 8.73e-03 171s
62 1.15195017e+05 7.66661497e+04 2.24e-02 3.84e-10 7.36e-03 174s
63 1.12166352e+05 7.78386246e+04 1.75e-02 3.10e-10 5.83e-03 176s
64 1.09659574e+05 7.84460407e+04 1.37e-02 2.70e-10 4.74e-03 179s
65 1.08802488e+05 7.91890014e+04 1.25e-02 2.20e-10 4.16e-03 181s
66 1.07484043e+05 7.99735263e+04 1.06e-02 1.65e-10 3.42e-03 183s
67 1.06564383e+05 8.00633077e+04 9.38e-03 1.59e-10 3.11e-03 186s
68 1.05216606e+05 8.05569473e+04 7.60e-03 1.26e-10 2.52e-03 188s
69 1.04396409e+05 8.09716407e+04 6.60e-03 9.84e-11 2.12e-03 191s
70 1.03666667e+05 8.11051762e+04 5.74e-03 8.94e-11 1.88e-03 192s
71 1.02998228e+05 8.14223306e+04 5.01e-03 6.48e-11 1.58e-03 195s
72 1.02259785e+05 8.16801295e+04 4.22e-03 4.82e-11 1.30e-03 197s
73 1.01020860e+05 8.18103371e+04 3.00e-03 4.17e-11 9.81e-04 200s
74 1.00100805e+05 8.19127169e+04 2.22e-03 3.36e-11 7.71e-04 202s
75 9.97905316e+04 8.19786141e+04 2.00e-03 2.91e-11 6.94e-04 204s
76 9.95109756e+04 8.20115079e+04 1.82e-03 2.67e-11 6.38e-04 207s
77 9.93215639e+04 8.20349328e+04 1.70e-03 2.50e-11 6.01e-04 209s
78 9.89743994e+04 8.20698617e+04 1.49e-03 2.30e-11 5.40e-04 211s
79 9.88276428e+04 8.21001096e+04 1.41e-03 2.08e-11 5.08e-04 214s
80 9.83610740e+04 8.21539612e+04 1.16e-03 1.70e-11 4.30e-04 216s
81 9.79258266e+04 8.21998075e+04 9.59e-04 1.43e-11 3.63e-04 218s
82 9.78504954e+04 8.22121000e+04 9.29e-04 1.34e-11 3.50e-04 221s
83 9.74804243e+04 8.22323334e+04 7.82e-04 1.22e-11 3.07e-04 223s
84 9.70659019e+04 8.22496879e+04 6.39e-04 1.13e-11 2.65e-04 225s
85 9.65051922e+04 8.22664096e+04 4.71e-04 1.03e-11 2.16e-04 228s
86 9.61030358e+04 8.22889849e+04 3.77e-04 8.94e-12 1.82e-04 230s
87 9.55896311e+04 8.23055013e+04 2.75e-04 8.13e-12 1.48e-04 232s
88 9.52720869e+04 8.23148797e+04 2.26e-04 7.48e-12 1.31e-04 235s
89 9.50019267e+04 8.23275658e+04 1.91e-04 6.54e-12 1.16e-04 237s
90 9.45682618e+04 8.23391910e+04 1.44e-04 7.11e-12 9.68e-05 240s
91 9.42104204e+04 8.23456445e+04 1.13e-04 7.16e-12 8.42e-05 242s
92 9.39106712e+04 8.23519891e+04 9.21e-05 8.98e-12 7.46e-05 244s
93 9.36579863e+04 8.23601042e+04 7.73e-05 8.98e-12 6.60e-05 247s
94 9.34271827e+04 8.23659260e+04 6.60e-05 9.27e-12 5.93e-05 249s
95 9.31714119e+04 8.23725089e+04 5.54e-05 1.19e-11 5.23e-05 252s
96 9.29014381e+04 8.23768281e+04 4.66e-05 1.40e-11 4.66e-05 254s
97 9.24145105e+04 8.23796564e+04 3.34e-05 1.59e-11 3.91e-05 256s
98 9.21679670e+04 8.23848872e+04 2.78e-05 1.72e-11 3.44e-05 259s
99 9.27432083e+04 8.23889109e+04 1.97e-05 1.54e-11 7.99e-05 261s
100 9.26067101e+04 8.23936671e+04 1.64e-05 1.43e-11 7.73e-05 264s
101 9.24081120e+04 8.23962250e+04 1.29e-05 6.59e-12 7.01e-05 266s
102 9.21883339e+04 8.24003992e+04 9.60e-06 9.49e-12 6.27e-05 269s
103 9.19527361e+04 8.24032020e+04 6.45e-06 1.35e-11 5.19e-05 271s
104 9.18130582e+04 8.24044780e+04 5.02e-06 1.44e-11 4.59e-05 273s
105 9.04697360e+04 8.24060066e+04 3.02e-06 1.34e-11 3.25e-05 277s
106 8.96307798e+04 8.24074379e+04 2.02e-06 2.17e-11 3.07e-05 281s
107 8.94869257e+04 8.24088826e+04 1.87e-06 2.50e-11 3.02e-05 284s
108 8.90820341e+04 8.24108516e+04 1.45e-06 1.94e-11 2.44e-05 287s
109 8.86826506e+04 8.24113769e+04 1.09e-06 1.82e-11 1.71e-05 289s
110 8.84536518e+04 8.24121255e+04 9.54e-07 2.12e-11 1.52e-05 292s
111 8.80594865e+04 8.24127933e+04 7.23e-07 2.03e-11 1.14e-05 295s
112 8.79992495e+04 8.24134696e+04 6.94e-07 1.74e-11 1.10e-05 298s
113 8.75734300e+04 8.24139355e+04 4.99e-07 2.31e-11 7.79e-06 301s
114 8.71973182e+04 8.24143904e+04 3.84e-07 1.60e-11 5.87e-06 305s
115 8.68469274e+04 8.24146064e+04 2.94e-07 1.75e-11 4.50e-06 308s
116 8.66719024e+04 8.24149049e+04 2.60e-07 1.58e-11 3.93e-06 312s
117 8.66187053e+04 8.24149100e+04 2.51e-07 1.77e-11 3.80e-06 315s
118 8.64958014e+04 8.24149406e+04 2.30e-07 2.46e-11 3.50e-06 318s
119 8.62576088e+04 8.24152193e+04 1.97e-07 2.58e-11 2.92e-06 322s
120 8.56881546e+04 8.24154045e+04 1.36e-07 1.76e-11 1.87e-06 325s
121 8.51127388e+04 8.24156437e+04 9.24e-08 1.46e-11 1.15e-06 328s
122 8.43605570e+04 8.24157549e+04 4.61e-08 1.23e-11 6.01e-07 332s
123 8.41532118e+04 8.24158342e+04 4.15e-08 1.23e-11 5.02e-07 335s
124 8.36657060e+04 8.24158757e+04 2.75e-08 1.43e-11 3.47e-07 337s
125 8.33499164e+04 8.24158922e+04 2.26e-08 2.35e-11 2.81e-07 339s
126 8.32384909e+04 8.24159112e+04 2.16e-08 1.97e-11 2.57e-07 342s
127 8.28536367e+04 8.24159326e+04 1.60e-08 2.61e-11 1.93e-07 344s
128 8.26430045e+04 8.24159456e+04 2.55e-08 2.35e-11 1.67e-07 346s
129 8.30053447e+04 8.24159518e+04 2.56e-07 2.35e-11 4.85e-05 349s
130 8.29297218e+04 8.24159633e+04 2.49e-07 6.47e-11 3.63e-05 351s
131 8.28872247e+04 8.24159668e+04 2.45e-07 8.90e-11 3.57e-05 354s
132 8.28439993e+04 8.24159693e+04 2.40e-07 1.02e-10 3.55e-05 357s
133 8.28220942e+04 8.24159733e+04 2.32e-07 1.22e-10 3.40e-05 359s
134 8.27894390e+04 8.24159753e+04 2.09e-07 1.26e-10 3.04e-05 363s
135 8.27535386e+04 8.24159800e+04 1.84e-07 1.58e-10 2.48e-05 366s
136 8.27338055e+04 8.24159806e+04 7.13e-07 1.77e-10 2.22e-05 369s
137 8.26927295e+04 8.24159822e+04 7.49e-07 1.97e-10 1.75e-05 372s
138 8.26770296e+04 8.24159833e+04 8.29e-07 1.99e-10 1.59e-05 375s
139 8.26568475e+04 8.24159845e+04 8.79e-07 1.99e-10 1.41e-05 378s
140 8.26417347e+04 8.24159854e+04 5.93e-07 1.98e-10 1.26e-05 381s
141 8.26290452e+04 8.24159865e+04 5.47e-07 1.92e-10 1.16e-05 383s
142 8.26234366e+04 8.24159859e+04 5.19e-07 2.00e-10 1.09e-05 386s
143 8.26170429e+04 8.24159879e+04 5.16e-07 1.90e-10 1.04e-05 389s
144 8.26117264e+04 8.24159892e+04 6.24e-07 1.88e-10 9.66e-06 392s
145 8.26051923e+04 8.24159894e+04 7.26e-07 1.93e-10 9.02e-06 395s
146 8.25986632e+04 8.24159908e+04 1.04e-06 1.89e-10 8.40e-06 398s
147 8.25933273e+04 8.24159932e+04 1.01e-06 1.81e-10 7.74e-06 401s
148 8.25859332e+04 8.24159940e+04 1.28e-06 1.84e-10 7.04e-06 404s
149 8.25793071e+04 8.24159953e+04 1.04e-06 1.79e-10 6.56e-06 407s
150 8.25708188e+04 8.24159964e+04 9.75e-07 1.77e-10 6.01e-06 410s
151 8.25645429e+04 8.24159979e+04 9.18e-07 1.71e-10 5.60e-06 414s
152 8.25613510e+04 8.24159988e+04 8.64e-07 1.64e-10 5.30e-06 416s
153 8.25511410e+04 8.24160000e+04 7.74e-07 1.61e-10 4.79e-06 420s
154 8.25474969e+04 8.24160008e+04 7.02e-07 1.55e-10 4.52e-06 423s
155 8.25433066e+04 8.24160023e+04 6.61e-07 1.47e-10 4.31e-06 425s
156 8.25179846e+04 8.24160007e+04 8.10e-07 1.85e-10 3.22e-06 429s
157 8.25094491e+04 8.24160030e+04 8.99e-07 1.62e-10 2.71e-06 432s
158 8.24968789e+04 8.24160041e+04 7.33e-07 1.58e-10 2.35e-06 435s
159 8.24874022e+04 8.24160018e+04 6.56e-07 1.77e-10 2.15e-06 439s
160 8.24830501e+04 8.24160036e+04 6.26e-07 1.65e-10 2.07e-06 441s
161 8.24656773e+04 8.24160064e+04 6.39e-07 1.43e-10 1.67e-06 445s
162 8.24603693e+04 8.24160087e+04 6.02e-07 1.29e-10 1.63e-06 448s
163 8.24422170e+04 8.24160073e+04 8.55e-07 1.44e-10 1.25e-06 451s
164 8.24194375e+04 8.24160120e+04 6.26e-07 1.15e-10 3.85e-07 453s
165 8.24200525e+04 8.24160151e+04 4.99e-07 9.57e-11 5.93e-07 456s
166 8.24193440e+04 8.24160158e+04 4.70e-07 9.16e-11 5.41e-07 459s
167 8.24189631e+04 8.24160161e+04 6.72e-07 9.17e-11 5.30e-07 462s
168 8.24180500e+04 8.24160204e+04 5.58e-07 6.83e-11 5.02e-07 465s
169 8.24178568e+04 8.24160212e+04 4.84e-07 6.14e-11 4.73e-07 468s
170 8.24177387e+04 8.24160223e+04 4.84e-07 5.34e-11 4.63e-07 471s
171 8.24176342e+04 8.24160234e+04 4.64e-07 4.70e-11 4.51e-07 474s
172 8.24175124e+04 8.24160244e+04 4.78e-07 4.30e-11 4.27e-07 477s
173 8.24173806e+04 8.24160246e+04 4.35e-07 4.40e-11 3.93e-07 479s
174 8.24173076e+04 8.24160250e+04 5.42e-07 4.29e-11 3.76e-07 482s
175 8.24172066e+04 8.24160264e+04 5.12e-07 8.80e-11 3.59e-07 486s
176 8.24169140e+04 8.24160308e+04 2.82e-06 1.97e-10 2.87e-07 489s
177 8.24168652e+04 8.24160332e+04 2.69e-06 2.34e-10 2.78e-07 492s
178 8.24168496e+04 8.24160340e+04 2.64e-06 2.25e-10 2.75e-07 495s
179 8.24167472e+04 8.24160359e+04 2.36e-06 2.47e-10 2.44e-07 498s
180 8.24167174e+04 8.24160366e+04 2.27e-06 2.52e-10 2.35e-07 500s
181 8.24166852e+04 8.24160371e+04 2.18e-06 2.44e-10 2.25e-07 504s
182 8.24166191e+04 8.24160392e+04 1.98e-06 2.58e-10 2.04e-07 507s
183 8.24165350e+04 8.24160435e+04 6.46e-06 2.65e-10 1.77e-07 511s
184 8.24165125e+04 8.24160442e+04 5.87e-06 2.57e-10 1.69e-07 514s
185 8.24164832e+04 8.24160448e+04 1.94e-06 2.51e-10 1.59e-07 517s
186 8.24164638e+04 8.24160463e+04 1.91e-06 2.36e-10 1.52e-07 521s
187 8.24164607e+04 8.24160477e+04 1.90e-06 2.23e-10 1.51e-07 524s
188 8.24164479e+04 8.24160480e+04 1.84e-06 2.20e-10 1.47e-07 527s
189 8.24164457e+04 8.24160482e+04 1.83e-06 2.63e-11 1.46e-07 529s
190 8.24164432e+04 8.24160483e+04 1.83e-06 2.63e-11 1.45e-07 532s
191 8.24164330e+04 8.24160485e+04 1.79e-06 2.97e-11 1.41e-07 535s
192 8.24164277e+04 8.24160486e+04 1.77e-06 3.01e-11 1.39e-07 538s
193 8.24164094e+04 8.24160489e+04 1.68e-06 3.62e-11 1.33e-07 541s
194 8.24163843e+04 8.24160506e+04 1.56e-06 5.41e-11 1.24e-07 544s
195 8.24163758e+04 8.24160518e+04 1.67e-06 5.63e-11 1.21e-07 547s
196 8.24163654e+04 8.24160520e+04 1.61e-06 5.80e-11 1.17e-07 550s
197 8.24163653e+04 8.24160520e+04 1.61e-06 5.81e-11 1.17e-07 553s
198 8.24163392e+04 8.24160529e+04 1.49e-06 6.09e-11 1.07e-07 556s
199 8.24163267e+04 8.24160536e+04 1.43e-06 5.28e-11 1.02e-07 559s
200 8.24163247e+04 8.24160542e+04 1.42e-06 4.93e-11 1.02e-07 561s
201 8.24163043e+04 8.24160550e+04 1.35e-06 4.79e-11 9.39e-08 565s
202 8.24162811e+04 8.24160564e+04 1.22e-06 4.50e-11 8.50e-08 568s
203 8.24162616e+04 8.24160584e+04 1.12e-06 4.07e-11 7.73e-08 571s
204 8.24162555e+04 8.24160590e+04 1.08e-06 3.94e-11 7.48e-08 574s
205 8.24162497e+04 8.24160597e+04 1.05e-06 3.80e-11 7.25e-08 576s
206 8.24162347e+04 8.24160604e+04 9.72e-07 3.67e-11 6.66e-08 579s
207 8.24162301e+04 8.24160615e+04 9.43e-07 3.45e-11 6.46e-08 582s
208 8.24162206e+04 8.24160620e+04 8.79e-07 3.37e-11 6.09e-08 585s
209 8.24162173e+04 8.24160623e+04 8.59e-07 3.48e-11 5.95e-08 588s
210 8.24162120e+04 8.24160630e+04 8.29e-07 3.15e-11 5.73e-08 590s
211 8.24162072e+04 8.24160633e+04 8.05e-07 3.08e-11 5.54e-08 594s
212 8.24162026e+04 8.24160638e+04 7.84e-07 3.26e-11 5.35e-08 596s
213 8.24162020e+04 8.24160640e+04 7.80e-07 2.97e-11 5.32e-08 599s
214 8.24162004e+04 8.24160644e+04 7.71e-07 2.99e-11 5.25e-08 602s
215 8.24161909e+04 8.24160652e+04 9.29e-07 2.67e-11 4.86e-08 605s
216 8.24161877e+04 8.24160668e+04 9.03e-07 2.13e-11 4.69e-08 607s
217 8.24161785e+04 8.24160675e+04 8.24e-07 2.01e-11 4.31e-08 610s
218 8.24161718e+04 8.24160682e+04 2.37e-06 1.90e-11 4.03e-08 612s
219 8.24161662e+04 8.24160686e+04 2.25e-06 2.09e-11 3.80e-08 615s
220 8.24161573e+04 8.24160705e+04 2.03e-06 4.98e-11 3.39e-08 618s
221 8.24161533e+04 8.24160709e+04 1.92e-06 4.88e-11 3.22e-08 622s
222 8.24161466e+04 8.24160712e+04 1.76e-06 4.77e-11 2.95e-08 625s
223 8.24161403e+04 8.24160723e+04 1.60e-06 4.16e-11 2.66e-08 627s
224 8.24161345e+04 8.24160732e+04 9.34e-07 3.67e-11 2.40e-08 630s
225 8.24161308e+04 8.24160737e+04 1.72e-06 3.50e-11 2.24e-08 632s
226 8.24161276e+04 8.24160741e+04 1.59e-06 3.56e-11 2.10e-08 635s
227 8.24161267e+04 8.24160745e+04 1.56e-06 3.95e-11 2.05e-08 637s
228 8.24161215e+04 8.24160760e+04 1.37e-06 6.24e-11 1.79e-08 641s
229 8.24161188e+04 8.24160761e+04 1.66e-06 6.20e-11 1.68e-08 643s
230 8.24161137e+04 8.24160766e+04 1.44e-06 5.93e-11 1.46e-08 647s
231 8.24161107e+04 8.24160774e+04 1.29e-06 5.35e-11 1.31e-08 650s
232 8.24161089e+04 8.24160776e+04 1.21e-06 5.18e-11 1.24e-08 654s
233 8.24161082e+04 8.24160779e+04 1.18e-06 5.53e-11 1.20e-08 656s
234 8.24161070e+04 8.24160779e+04 1.12e-06 5.51e-11 1.15e-08 659s
235 8.24161055e+04 8.24160786e+04 1.05e-06 6.46e-11 1.06e-08 662s
236 8.24161054e+04 8.24160788e+04 1.05e-06 6.65e-11 1.05e-08 665s
237 8.24161050e+04 8.24160790e+04 1.03e-06 6.54e-11 1.03e-08 667s
238 8.24161025e+04 8.24160804e+04 1.65e-06 3.65e-11 8.77e-09 670s
239 8.24161005e+04 8.24160806e+04 1.47e-06 3.66e-11 7.87e-09 673s
240 8.24160988e+04 8.24160809e+04 1.32e-06 3.55e-11 7.11e-09 676s
241 8.24160981e+04 8.24160811e+04 1.25e-06 3.46e-11 6.74e-09 679s
242 8.24160979e+04 8.24160811e+04 1.23e-06 3.43e-11 6.63e-09 682s
243 8.24160975e+04 8.24160812e+04 1.19e-06 3.40e-11 6.45e-09 684s
244 8.24160973e+04 8.24160812e+04 1.18e-06 3.38e-11 6.38e-09 687s
245 8.24160972e+04 8.24160813e+04 1.17e-06 4.08e-11 6.31e-09 689s
246 8.24160972e+04 8.24160813e+04 1.17e-06 4.30e-11 6.28e-09 692s
247 8.24160969e+04 8.24160814e+04 1.10e-06 3.26e-11 6.14e-09 694s
248 8.24160953e+04 8.24160815e+04 9.85e-07 2.21e-11 5.50e-09 697s
249 8.24160939e+04 8.24160817e+04 1.36e-06 1.99e-11 4.81e-09 700s
250 8.24160933e+04 8.24160820e+04 1.26e-06 1.83e-11 4.47e-09 703s
251 8.24160933e+04 8.24160822e+04 1.21e-06 2.40e-11 4.40e-09 706s
252 8.24160933e+04 8.24160822e+04 1.20e-06 2.60e-11 4.38e-09 709s
253 8.24160931e+04 8.24160822e+04 1.16e-06 2.92e-11 4.33e-09 712s
254 8.24160929e+04 8.24160822e+04 1.15e-06 2.03e-11 4.24e-09 715s
255 8.24160924e+04 8.24160821e+04 1.10e-06 2.74e-11 4.06e-09 717s
256 8.24160923e+04 8.24160826e+04 1.08e-06 3.78e-11 3.83e-09 720s
257 8.24160906e+04 8.24160827e+04 9.38e-07 4.53e-11 3.12e-09 723s
258 8.24160905e+04 8.24160828e+04 9.22e-07 4.82e-11 3.05e-09 726s
259 8.24160905e+04 8.24160828e+04 9.20e-07 4.80e-11 3.04e-09 728s
260 8.24160904e+04 8.24160829e+04 1.76e-06 4.98e-11 2.97e-09 731s
261 8.24160904e+04 8.24160829e+04 1.76e-06 3.70e-11 2.97e-09 734s
262 8.24160904e+04 8.24160830e+04 1.69e-06 3.70e-11 2.92e-09 737s
Barrier solved model in 262 iterations and 736.86 seconds (1369.04 work units)
Optimal objective 8.24160904e+04
Crossover log...
430288 DPushes remaining with DInf 0.0000000e+00 738s
135504 DPushes remaining with DInf 0.0000000e+00 740s
14823 DPushes remaining with DInf 0.0000000e+00 745s
5398 DPushes remaining with DInf 0.0000000e+00 750s
0 DPushes remaining with DInf 0.0000000e+00 756s
Warning: Markowitz tolerance tightened to 0.25
165386 PPushes remaining with PInf 1.6964352e+00 756s
137422 PPushes remaining with PInf 2.2121439e+00 766s
126247 PPushes remaining with PInf 2.1577469e+00 776s
119120 PPushes remaining with PInf 2.1283277e+00 781s
112851 PPushes remaining with PInf 2.1202912e+00 788s
111091 PPushes remaining with PInf 2.1181871e+00 791s
106685 PPushes remaining with PInf 1.3981407e+00 796s
83562 PPushes remaining with PInf 2.5799430e-01 801s
68060 PPushes remaining with PInf 1.4327056e-01 805s
46301 PPushes remaining with PInf 2.8839526e-01 810s
27692 PPushes remaining with PInf 2.3127559e+02 817s
20885 PPushes remaining with PInf 2.0328073e+02 820s
13613 PPushes remaining with PInf 6.0824676e+02 826s
10767 PPushes remaining with PInf 1.7361963e+03 830s
3332 PPushes remaining with PInf 1.5442277e+03 837s
0 PPushes remaining with PInf 1.4836794e+03 839s
Push phase complete: Pinf 1.4836794e+03, Dinf 2.0118940e+02 839s
Iteration Objective Primal Inf. Dual Inf. Time
470901 8.2416100e+04 0.000000e+00 2.011894e+02 840s
471451 8.2416097e+04 0.000000e+00 8.737139e+01 844s
471981 8.2416087e+04 0.000000e+00 4.344464e+04 848s
472551 8.2416082e+04 0.000000e+00 2.592114e-01 853s
473131 8.2416080e+04 0.000000e+00 3.131904e+02 857s
473735 8.2416078e+04 0.000000e+00 1.430948e-02 861s
474195 8.2416077e+04 0.000000e+00 2.402066e+00 866s
474615 8.2416076e+04 0.000000e+00 7.812221e-02 871s
475071 8.2416088e+04 1.565372e+03 0.000000e+00 875s
475219 8.2416088e+04 0.000000e+00 2.224708e-03 880s
Extra simplex iterations after uncrush: 4
475412 8.2416088e+04 0.000000e+00 0.000000e+00 886s
Solved in 475412 iterations and 885.61 seconds (1933.96 work units)
Optimal objective 8.241608804e+04
Cost:82416.088042
Any insights would be greatly appreciated.
Thank you,
Zhongfan Gu
0
-
Hello Jaromił,
Thank you very much for your insights in your previous response. Following your advice, I attempted to set
Presolveto 2 andBarHomogeneousto 1 in order to improve the solve process. Unfortunately, these settings did not resolve the issue. Below is the solver log from my latest attempt:Solver Log with Presolve=2 and BarHomogeneous=1:
Set parameter Username
Set parameter Method to value 2
Set parameter BarHomogeneous to value 1
Set parameter Crossover to value 0
Set parameter NodefileDir to value ""
Set parameter Presolve to value 2
Set parameter TuneTimeLimit to value 1e+100
Academic license - for non-commercial use only - expires 2024-11-02
Gurobi Optimizer version 10.0.3 build v10.0.3rc0 (win64)
CPU model: 13th Gen Intel(R) Core(TM) i7-13700K, instruction set [SSE2|AVX|AVX2]
Thread count: 16 physical cores, 24 logical processors, using up to 24 threads
Optimize a model with 4702180 rows, 2210651 columns and 19350520 nonzeros
Model fingerprint: 0x34eacf5d
Coefficient statistics:
Matrix range [2e-05, 1e+01]
Objective range [2e-03, 2e+02]
Bounds range [0e+00, 0e+00]
RHS range [2e-02, 8e+04]
Presolve removed 1022585 rows and 3101192 columns (presolve time = 5s) ...
Presolve removed 1022585 rows and 3117081 columns
Presolve time: 8.21s
Presolved: 1188066 rows, 1585099 columns, 11208382 nonzeros
Elapsed ordering time = 6s
Elapsed ordering time = 27s
Elapsed ordering time = 30s
Elapsed ordering time = 35s
Elapsed ordering time = 40s
Elapsed ordering time = 45s
Ordering time: 46.57s
Barrier statistics:
Dense cols : 53
Free vars : 185912
AA' NZ : 2.455e+07
Factor NZ : 1.298e+09 (roughly 12.0 GB of memory)
Factor Ops : 5.358e+12 (roughly 10 seconds per iteration)
Threads : 16
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.60479324e+11 7.57738388e+11 7.72e+06 1.07e+05 1.91e+08 73s
1 1.21109862e+11 6.73035539e+11 6.61e+06 8.97e+04 1.62e+08 93s
2 9.85913920e+10 6.11755544e+11 5.98e+06 7.33e+04 1.41e+08 107s
3 6.00163845e+10 5.98520307e+11 4.89e+06 6.80e+04 1.21e+08 121s
4 1.75191160e+10 3.52742091e+11 2.36e+06 4.11e+04 4.26e+07 137s
5 3.41558696e+09 2.41070656e+11 1.54e+06 2.89e+04 2.36e+07 153s
6 -4.61302970e+09 1.67298976e+11 1.08e+06 2.08e+04 1.46e+07 170s
7 -9.20544135e+09 1.20751423e+11 8.04e+05 1.57e+04 1.00e+07 186s
8 -1.19472908e+10 8.84384931e+10 6.29e+05 1.21e+04 7.37e+06 202s
9 -1.36316037e+10 6.58322035e+10 5.09e+05 9.62e+03 5.70e+06 218s
10 -1.48106222e+10 4.38253715e+10 4.17e+05 7.16e+03 4.32e+06 233s
11 -1.52718259e+10 2.50266824e+10 2.81e+05 4.92e+03 2.80e+06 249s
12 -1.47334706e+10 1.67201630e+10 2.50e+05 3.83e+03 2.26e+06 264s
13 -1.33710472e+10 1.12803835e+10 2.02e+05 2.97e+03 1.70e+06 280s
14 -1.14487986e+10 5.39878203e+09 1.53e+05 2.00e+03 1.13e+06 296s
15 -9.61016574e+09 2.85600599e+09 1.23e+05 1.39e+03 7.80e+05 311s
16 -7.16583140e+09 1.48600301e+09 8.48e+04 9.23e+02 4.71e+05 327s
17 -5.29706871e+09 6.33326160e+08 5.93e+04 5.98e+02 2.86e+05 343s
18 -4.34620399e+09 3.16007484e+08 4.75e+04 4.29e+02 2.01e+05 359s
19 -3.25798216e+09 1.39257273e+08 3.48e+04 3.03e+02 1.32e+05 374s
20 -2.30719920e+09 3.63081417e+07 2.38e+04 1.99e+02 7.97e+04 390s
21 -9.82494673e+08 -9.82959191e+06 1.05e+04 8.36e+01 2.64e+04 406s
22 -3.43912244e+08 -1.71192615e+07 3.13e+03 5.60e+01 8.39e+03 421s
23 -1.53412626e+08 -1.66452817e+07 1.25e+03 1.17e+01 1.29e+03 437s
24 -2.84053721e+07 -4.52684484e+06 2.45e+02 3.65e+00 1.49e+02 452s
25 -8.75182272e+06 -1.93250344e+06 8.31e+01 1.88e+00 4.12e+01 469s
26 -8.18685360e+06 -1.81224925e+06 7.83e+01 1.80e+00 3.84e+01 484s
27 -5.40620236e+06 -9.76699295e+05 5.37e+01 1.19e+00 2.20e+01 503s
28 -5.39494862e+06 -9.71119685e+05 5.36e+01 1.19e+00 2.19e+01 519s
29 -4.80174437e+06 -8.02124470e+05 4.86e+01 1.09e+00 1.93e+01 535s
30 -4.16117444e+06 -7.79402961e+05 4.36e+01 1.02e+00 1.65e+01 552s
31 -4.15887303e+06 -7.78548837e+05 4.36e+01 1.02e+00 1.65e+01 569s
32 -4.10914424e+06 -7.67597388e+05 4.31e+01 1.01e+00 1.63e+01 585s
33 -4.10921280e+06 -7.80214595e+05 4.31e+01 1.01e+00 1.62e+01 602s
34 -4.06349326e+06 -7.57262002e+05 4.25e+01 9.69e-01 1.56e+01 619s
35 -4.03270130e+06 -7.17528269e+05 4.22e+01 9.41e-01 1.53e+01 636s
36 -4.02500966e+06 -7.15853257e+05 4.21e+01 9.40e-01 1.52e+01 653s
37 -3.98868806e+06 -7.13562049e+05 4.17e+01 9.36e-01 1.51e+01 669s
38 -3.96695903e+06 -6.90377090e+05 4.16e+01 9.27e-01 1.50e+01 685s
39 -3.96701175e+06 -6.90439169e+05 4.16e+01 9.27e-01 1.50e+01 702s
40 -3.95809051e+06 -6.87089945e+05 4.15e+01 9.24e-01 1.49e+01 718s
41 -3.92056759e+06 -6.80601808e+05 4.11e+01 9.19e-01 1.48e+01 735s
42 -3.59511269e+06 -6.10259913e+05 3.85e+01 8.83e-01 1.37e+01 751s
43 -3.56336018e+06 -5.79478465e+05 3.82e+01 8.65e-01 1.34e+01 767s
44 -3.38574110e+06 -5.37438280e+05 3.65e+01 8.30e-01 1.27e+01 785s
45 -3.14945437e+06 -5.14342101e+05 3.47e+01 8.21e-01 1.21e+01 802s
46 -3.12510512e+06 -5.12717844e+05 3.45e+01 8.18e-01 1.20e+01 818s
47 -3.11779672e+06 -5.12325358e+05 3.44e+01 8.18e-01 1.20e+01 835s
48 -3.11771320e+06 -5.15607238e+05 3.44e+01 8.18e-01 1.20e+01 851s
49 -3.11724946e+06 -5.15736737e+05 3.44e+01 8.18e-01 1.20e+01 867s
50 -2.95164538e+06 -5.08777015e+05 3.30e+01 8.14e-01 1.16e+01 883s
51 -2.95042652e+06 -5.11441072e+05 3.30e+01 8.13e-01 1.15e+01 900s
52 -2.94344853e+06 -5.07088636e+05 3.29e+01 8.09e-01 1.15e+01 916s
53 -2.94283875e+06 -5.07043143e+05 3.29e+01 8.09e-01 1.15e+01 932s
54 -2.69681566e+06 -4.74089018e+05 3.06e+01 7.83e-01 1.07e+01 948s
55 -2.69677371e+06 -4.77322909e+05 3.06e+01 7.83e-01 1.07e+01 964s
56 -2.69489436e+06 -4.77037944e+05 3.05e+01 7.83e-01 1.07e+01 980s
57 -2.69487857e+06 -4.77233905e+05 3.05e+01 7.83e-01 1.07e+01 997s
58 -2.65265231e+06 -4.62995752e+05 3.02e+01 7.76e-01 1.05e+01 1014s
59 -2.63543433e+06 -4.60964416e+05 3.00e+01 7.72e-01 1.05e+01 1030s
60 -2.63518532e+06 -4.60851863e+05 3.00e+01 7.72e-01 1.05e+01 1047s
61 -2.61846361e+06 -4.51169956e+05 2.99e+01 7.65e-01 1.04e+01 1063s
62 -2.61755578e+06 -4.49731201e+05 2.99e+01 7.65e-01 1.04e+01 1080s
63 -2.61766325e+06 -4.49864132e+05 2.99e+01 7.65e-01 1.04e+01 1097s
64 -2.61765269e+06 -4.49864100e+05 2.99e+01 7.65e-01 1.04e+01 1113s
65 -2.61729669e+06 -4.49742897e+05 2.99e+01 7.64e-01 1.04e+01 1130s
66 -2.61698651e+06 -4.49547872e+05 2.98e+01 7.64e-01 1.03e+01 1146s
67 -2.61186068e+06 -4.47552723e+05 2.98e+01 7.63e-01 1.03e+01 1162s
68 -2.61153466e+06 -4.47390110e+05 2.98e+01 7.63e-01 1.03e+01 1179s
69 -2.61150254e+06 -4.47374768e+05 2.98e+01 7.63e-01 1.03e+01 1195s
70 -2.61035489e+06 -4.46276398e+05 2.98e+01 7.62e-01 1.03e+01 1211s
71 -2.60997570e+06 -4.46233704e+05 2.98e+01 7.62e-01 1.03e+01 1227s
72 -2.60971095e+06 -4.46541649e+05 2.98e+01 7.62e-01 1.03e+01 1244s
73 -2.55590200e+06 -4.30380743e+05 2.93e+01 7.51e-01 1.01e+01 1261s
74 -2.54858034e+06 -4.28133320e+05 2.92e+01 7.49e-01 1.01e+01 1277s
75 -2.54856964e+06 -4.28116394e+05 2.92e+01 7.49e-01 1.01e+01 1294s
76 -2.49577564e+06 -4.21757482e+05 2.87e+01 7.44e-01 9.90e+00 1310s
77 -2.49429894e+06 -4.22157375e+05 2.87e+01 7.44e-01 9.89e+00 1326s
78 -2.49420023e+06 -4.22117884e+05 2.87e+01 7.44e-01 9.89e+00 1342s
79 -2.46348056e+06 -4.20766591e+05 2.84e+01 7.43e-01 9.82e+00 1359s
80 -2.44563763e+06 -4.20462693e+05 2.82e+01 7.42e-01 9.77e+00 1375s
81 -2.40338790e+06 -4.09556693e+05 2.78e+01 7.30e-01 9.57e+00 1391s
82 -2.40337958e+06 -4.09537887e+05 2.78e+01 7.30e-01 9.57e+00 1408s
83 -2.40327229e+06 -4.09507703e+05 2.78e+01 7.30e-01 9.57e+00 1424s
84 -2.37564141e+06 -3.98120519e+05 2.75e+01 7.21e-01 9.42e+00 1441s
85 -2.32336000e+06 -3.79622950e+05 2.71e+01 7.09e-01 9.20e+00 1457s
86 -2.32327542e+06 -3.79596001e+05 2.71e+01 7.09e-01 9.20e+00 1473s
87 -2.31977989e+06 -3.78777766e+05 2.70e+01 7.08e-01 9.18e+00 1489s
88 -2.15466741e+06 -3.47562192e+05 2.54e+01 6.77e-01 8.56e+00 1505s
89 -2.15127581e+06 -3.41822874e+05 2.53e+01 6.71e-01 8.50e+00 1521s
90 -2.15134121e+06 -3.41851570e+05 2.53e+01 6.71e-01 8.50e+00 1538s
91 -2.14335907e+06 -3.28429645e+05 2.52e+01 6.59e-01 8.38e+00 1554s
92 -2.14332971e+06 -3.28418440e+05 2.52e+01 6.59e-01 8.38e+00 1571s
93 -2.14340283e+06 -3.28447718e+05 2.52e+01 6.59e-01 8.38e+00 1587s
94 -2.12446871e+06 -3.26303253e+05 2.50e+01 6.57e-01 8.32e+00 1603s
95 -2.12097513e+06 -3.25610031e+05 2.50e+01 6.56e-01 8.30e+00 1619s
96 -2.07242989e+06 -3.15183894e+05 2.45e+01 6.45e-01 8.11e+00 1635s
97 -2.07107577e+06 -3.13938753e+05 2.45e+01 6.44e-01 8.09e+00 1651s
98 -2.06415882e+06 -3.11963176e+05 2.44e+01 6.42e-01 8.06e+00 1668s
99 -2.06382595e+06 -3.11846647e+05 2.44e+01 6.42e-01 8.05e+00 1684s
100 -2.06320459e+06 -3.11758464e+05 2.44e+01 6.42e-01 8.05e+00 1700s
101 -2.06303559e+06 -3.11734356e+05 2.44e+01 6.41e-01 8.05e+00 1716s
102 -2.06251522e+06 -3.11652767e+05 2.44e+01 6.41e-01 8.05e+00 1732s
103 -2.06232646e+06 -3.11684840e+05 2.44e+01 6.41e-01 8.05e+00 1748s
104 -2.06219853e+06 -3.11638448e+05 2.44e+01 6.41e-01 8.05e+00 1764s
105 -2.06048889e+06 -3.11369199e+05 2.44e+01 6.41e-01 8.04e+00 1781s
106 -2.05935453e+06 -3.10543284e+05 2.44e+01 6.40e-01 8.03e+00 1797s
107 -2.05771976e+06 -3.10122332e+05 2.44e+01 6.40e-01 8.03e+00 1813s
108 -2.05532892e+06 -3.09211873e+05 2.43e+01 6.39e-01 8.01e+00 1829s
109 -2.05521170e+06 -3.09175282e+05 2.43e+01 6.39e-01 8.01e+00 1845s
110 -2.04880624e+06 -3.08132091e+05 2.43e+01 6.38e-01 7.99e+00 1862s
111 -2.04657729e+06 -3.07600552e+05 2.42e+01 6.37e-01 7.98e+00 1878s
112 -2.04658064e+06 -3.07601710e+05 2.42e+01 6.37e-01 7.98e+00 1894s
113 -2.04651589e+06 -3.07598513e+05 2.42e+01 6.37e-01 7.98e+00 1911s
114 -2.04653143e+06 -3.07604570e+05 2.42e+01 6.37e-01 7.98e+00 1927s
115 -2.04587714e+06 -3.07430562e+05 2.42e+01 6.37e-01 7.98e+00 1944s
116 -2.04319380e+06 -3.06168647e+05 2.42e+01 6.36e-01 7.96e+00 1960s
Barrier performed 116 iterations in 1960.01 seconds (3166.22 work units)
Numerical trouble encountered
Hmm, something went wrong!
ans =
'Numerical problems (learn to debug) (GUROBI)'As you can see, the problem still remains unresolved. Could you provide further guidance on how to proceed? Any additional suggestions or tweaks that could help make the model solvable without the crossover step would be greatly appreciated.
Besides, I agree with your suggestion that we should not disable the crossover step unless there's a compelling reason to do so. However, I'm encountering a significant issue with the solve time when I modify constraints on just 8 variables.
When I change the upper bounds of these variables (either increasing or decreasing them), the crossover phase takes more than 400,000 seconds and continues to run, which severely impacts the efficiency of the program. This has forced me to look into other methods to reduce solve time, such as disabling the crossover step, although I understand this affects the numerical stability of the barrier method.
Given that the barrier method is highly sensitive to numerical stability, I was wondering if you could advise on how to identify the specific values that are causing instability within the barrier method. Are there diagnostic tools or methods available to pinpoint these problematic values?
Any guidance on improving the solve time while maintaining the integrity of the solution would be greatly appreciated.
Thank you once again for your support.
Best regards,
Zhongfan Gu
1 -
Hi Zhongfan Gu,
From my understanding, both approaches should theoretically yield the same optimal solution, but this does not seem to be the case here. Could someone please explain why this discrepancy might occur and suggest any strategies to ensure feasibility without the crossover step?
Theoretically, yes, practically, no. The Barrier algorithm is quite prone to numerical challenges. The difference you see most likely comes from the fact that presolve performs slightly different if no crossover is requested (the presolve statistics are different). When crossover is turned on, Gurobi performs a few more presolve reductions by default, which in your case seem to help the Barrier algorithm.
You could try setting Presolve=2 and/or BarHomogeneous=1 for your Crossover=0 run. Presolve=2 tells Gurobi to perform more presolve reductions on the model. BarHomogeneous is a more careful version of the standard Barrier algorithm, which should avoid the numerical trouble. The homogeneous Barrier algorithm checks for infeasibility and unboundedness at every iteration of the Barrier algorithm.
In general, if there is no good reason for turning off Crossover, it is recommended to use it. The Crossover phase can clean up small constraint violations in the Barrier solution and can give a "cleaner" solution. "Cleaner" here means that more variables are at their bounds compared to a Barrier solution.
Best regards,
Jaromił0 -
Hi Zhongfan Gu,
As you can see, the problem still remains unresolved. Could you provide further guidance on how to proceed?
That's interesting. You could try running without the Presolve=2 setting, but only with BarHomogeneous=1.
Besides, I agree with your suggestion that we should not disable the crossover step unless there's a compelling reason to do so. However, I'm encountering a significant issue with the solve time when I modify constraints on just 8 variables.
When I change the upper bounds of these variables (either increasing or decreasing them), the crossover phase takes more than 400,000 seconds and continues to run, which severely impacts the efficiency of the program. This has forced me to look into other methods to reduce solve time, such as disabling the crossover step, although I understand this affects the numerical stability of the barrier method.
This sounds very suspicious. Could you please share the models, such that we could have a look on our side? In particular, could you share MPS files of the model that solves nicely with Crossover turned on and the model where you modify the constraints/variables? Could you please then point to which constraints/variables you exactly modify? You can generate MPS files via the write method. Note that uploading files in the Community Forum is not possible but we discuss an alternative in Posting to the Community Forum.
Are there diagnostic tools or methods available to pinpoint these problematic values?
You could try experimenting with the NumericFocus parameter. This would however not pinpoint the source of numerical issues. We provide a Python open source package called gurobi-modelanalyzer, which you might want to try out to find the source of numerical trouble in your model. See the corresponding docs for additional information.
Best regards,
Jaromił0 -
Hello Jaromił,
Firstly, I would like to extend my sincere gratitude for your assistance.
I have attempted setting
BarHomogeneous=1as suggested, but unfortunately, this does not seem to help with the correct solving of the program.Below are the specific solver logs:
Set parameter Username
Set parameter Method to value 2
Set parameter BarHomogeneous to value 1
Set parameter Crossover to value 0
Set parameter NodefileDir to value ""
Set parameter TuneTimeLimit to value 1e+100
Academic license - for non-commercial use only - expires 2024-11-02
Gurobi Optimizer version 10.0.3 build v10.0.3rc0 (win64)
CPU model: 13th Gen Intel(R) Core(TM) i7-13700K, instruction set [SSE2|AVX|AVX2]
Thread count: 16 physical cores, 24 logical processors, using up to 24 threads
Optimize a model with 4702180 rows, 2210651 columns and 19350520 nonzeros
Model fingerprint: 0x34eacf5d
Coefficient statistics:
Matrix range [2e-05, 1e+01]
Objective range [2e-03, 2e+02]
Bounds range [0e+00, 0e+00]
RHS range [2e-02, 8e+04]
Presolve removed 1022585 rows and 3117081 columns
Presolve time: 4.72s
Presolved: 1188066 rows, 1585099 columns, 11208382 nonzeros
Elapsed ordering time = 6s
Elapsed ordering time = 29s
Elapsed ordering time = 30s
Elapsed ordering time = 35s
Elapsed ordering time = 40s
Elapsed ordering time = 45s
Ordering time: 50.03s
Barrier statistics:
Dense cols : 53
Free vars : 185912
AA' NZ : 2.455e+07
Factor NZ : 1.298e+09 (roughly 12.0 GB of memory)
Factor Ops : 5.358e+12 (roughly 10 seconds per iteration)
Threads : 16
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.60479324e+11 7.57738388e+11 7.72e+06 1.07e+05 1.91e+08 73s
1 1.21109862e+11 6.73035539e+11 6.61e+06 8.97e+04 1.62e+08 92s
2 9.85913920e+10 6.11755544e+11 5.98e+06 7.33e+04 1.41e+08 106s
3 6.00163845e+10 5.98520307e+11 4.89e+06 6.80e+04 1.21e+08 121s
4 1.75191160e+10 3.52742091e+11 2.36e+06 4.11e+04 4.26e+07 137s
5 3.41558696e+09 2.41070656e+11 1.54e+06 2.89e+04 2.36e+07 153s
6 -4.61302970e+09 1.67298976e+11 1.08e+06 2.08e+04 1.46e+07 170s
7 -9.20544135e+09 1.20751423e+11 8.04e+05 1.57e+04 1.00e+07 186s
8 -1.19472908e+10 8.84384931e+10 6.29e+05 1.21e+04 7.37e+06 202s
9 -1.36316037e+10 6.58322035e+10 5.09e+05 9.62e+03 5.70e+06 217s
10 -1.48106222e+10 4.38253715e+10 4.17e+05 7.16e+03 4.32e+06 233s
11 -1.52718259e+10 2.50266824e+10 2.81e+05 4.92e+03 2.80e+06 248s
12 -1.47334706e+10 1.67201630e+10 2.50e+05 3.83e+03 2.26e+06 264s
13 -1.33710472e+10 1.12803835e+10 2.02e+05 2.97e+03 1.70e+06 279s
14 -1.14487986e+10 5.39878203e+09 1.53e+05 2.00e+03 1.13e+06 295s
15 -9.61016574e+09 2.85600599e+09 1.23e+05 1.39e+03 7.80e+05 311s
16 -7.16583140e+09 1.48600301e+09 8.48e+04 9.23e+02 4.71e+05 327s
17 -5.29706871e+09 6.33326160e+08 5.93e+04 5.98e+02 2.86e+05 342s
18 -4.34620399e+09 3.16007484e+08 4.75e+04 4.29e+02 2.01e+05 358s
19 -3.25798216e+09 1.39257273e+08 3.48e+04 3.03e+02 1.32e+05 374s
20 -2.30719920e+09 3.63081417e+07 2.38e+04 1.99e+02 7.97e+04 389s
21 -9.82494673e+08 -9.82959191e+06 1.05e+04 8.36e+01 2.64e+04 405s
22 -3.43912244e+08 -1.71192615e+07 3.13e+03 5.60e+01 8.39e+03 421s
23 -1.53412626e+08 -1.66452817e+07 1.25e+03 1.17e+01 1.29e+03 436s
24 -2.84053721e+07 -4.52684484e+06 2.45e+02 3.65e+00 1.49e+02 451s
25 -8.75182272e+06 -1.93250344e+06 8.31e+01 1.88e+00 4.12e+01 468s
26 -8.18685360e+06 -1.81224925e+06 7.83e+01 1.80e+00 3.84e+01 483s
27 -5.40620236e+06 -9.76699295e+05 5.37e+01 1.19e+00 2.20e+01 503s
28 -5.39494862e+06 -9.71119685e+05 5.36e+01 1.19e+00 2.19e+01 518s
29 -4.80174437e+06 -8.02124470e+05 4.86e+01 1.09e+00 1.93e+01 534s
30 -4.16117444e+06 -7.79402961e+05 4.36e+01 1.02e+00 1.65e+01 551s
31 -4.15887303e+06 -7.78548837e+05 4.36e+01 1.02e+00 1.65e+01 568s
32 -4.10914424e+06 -7.67597388e+05 4.31e+01 1.01e+00 1.63e+01 585s
33 -4.10921280e+06 -7.80214595e+05 4.31e+01 1.01e+00 1.62e+01 601s
34 -4.06349326e+06 -7.57262002e+05 4.25e+01 9.69e-01 1.56e+01 619s
35 -4.03270130e+06 -7.17528269e+05 4.22e+01 9.41e-01 1.53e+01 636s
36 -4.02500966e+06 -7.15853257e+05 4.21e+01 9.40e-01 1.52e+01 653s
37 -3.98868806e+06 -7.13562049e+05 4.17e+01 9.36e-01 1.51e+01 669s
38 -3.96695903e+06 -6.90377090e+05 4.16e+01 9.27e-01 1.50e+01 686s
39 -3.96701175e+06 -6.90439169e+05 4.16e+01 9.27e-01 1.50e+01 703s
40 -3.95809051e+06 -6.87089945e+05 4.15e+01 9.24e-01 1.49e+01 719s
41 -3.92056759e+06 -6.80601808e+05 4.11e+01 9.19e-01 1.48e+01 735s
42 -3.59511269e+06 -6.10259913e+05 3.85e+01 8.83e-01 1.37e+01 751s
43 -3.56336018e+06 -5.79478465e+05 3.82e+01 8.65e-01 1.34e+01 767s
44 -3.38574110e+06 -5.37438280e+05 3.65e+01 8.30e-01 1.27e+01 785s
45 -3.14945437e+06 -5.14342101e+05 3.47e+01 8.21e-01 1.21e+01 802s
46 -3.12510512e+06 -5.12717844e+05 3.45e+01 8.18e-01 1.20e+01 818s
47 -3.11779672e+06 -5.12325358e+05 3.44e+01 8.18e-01 1.20e+01 835s
48 -3.11771320e+06 -5.15607238e+05 3.44e+01 8.18e-01 1.20e+01 851s
49 -3.11724946e+06 -5.15736737e+05 3.44e+01 8.18e-01 1.20e+01 867s
50 -2.95164538e+06 -5.08777015e+05 3.30e+01 8.14e-01 1.16e+01 883s
51 -2.95042652e+06 -5.11441072e+05 3.30e+01 8.13e-01 1.15e+01 900s
52 -2.94344853e+06 -5.07088636e+05 3.29e+01 8.09e-01 1.15e+01 916s
53 -2.94283875e+06 -5.07043143e+05 3.29e+01 8.09e-01 1.15e+01 932s
54 -2.69681566e+06 -4.74089018e+05 3.06e+01 7.83e-01 1.07e+01 948s
55 -2.69677371e+06 -4.77322909e+05 3.06e+01 7.83e-01 1.07e+01 964s
56 -2.69489436e+06 -4.77037944e+05 3.05e+01 7.83e-01 1.07e+01 980s
57 -2.69487857e+06 -4.77233905e+05 3.05e+01 7.83e-01 1.07e+01 997s
58 -2.65265231e+06 -4.62995752e+05 3.02e+01 7.76e-01 1.05e+01 1014s
59 -2.63543433e+06 -4.60964416e+05 3.00e+01 7.72e-01 1.05e+01 1030s
60 -2.63518532e+06 -4.60851863e+05 3.00e+01 7.72e-01 1.05e+01 1047s
61 -2.61846361e+06 -4.51169956e+05 2.99e+01 7.65e-01 1.04e+01 1064s
62 -2.61755578e+06 -4.49731201e+05 2.99e+01 7.65e-01 1.04e+01 1082s
63 -2.61766325e+06 -4.49864132e+05 2.99e+01 7.65e-01 1.04e+01 1099s
64 -2.61765269e+06 -4.49864100e+05 2.99e+01 7.65e-01 1.04e+01 1115s
65 -2.61729669e+06 -4.49742897e+05 2.99e+01 7.64e-01 1.04e+01 1132s
66 -2.61698651e+06 -4.49547872e+05 2.98e+01 7.64e-01 1.03e+01 1148s
67 -2.61186068e+06 -4.47552723e+05 2.98e+01 7.63e-01 1.03e+01 1165s
68 -2.61153466e+06 -4.47390110e+05 2.98e+01 7.63e-01 1.03e+01 1182s
69 -2.61150254e+06 -4.47374768e+05 2.98e+01 7.63e-01 1.03e+01 1200s
70 -2.61035489e+06 -4.46276398e+05 2.98e+01 7.62e-01 1.03e+01 1216s
71 -2.60997570e+06 -4.46233704e+05 2.98e+01 7.62e-01 1.03e+01 1233s
72 -2.60971095e+06 -4.46541649e+05 2.98e+01 7.62e-01 1.03e+01 1250s
73 -2.55590200e+06 -4.30380743e+05 2.93e+01 7.51e-01 1.01e+01 1268s
74 -2.54858034e+06 -4.28133320e+05 2.92e+01 7.49e-01 1.01e+01 1285s
75 -2.54856964e+06 -4.28116394e+05 2.92e+01 7.49e-01 1.01e+01 1302s
76 -2.49577564e+06 -4.21757482e+05 2.87e+01 7.44e-01 9.90e+00 1318s
77 -2.49429894e+06 -4.22157375e+05 2.87e+01 7.44e-01 9.89e+00 1336s
78 -2.49420023e+06 -4.22117884e+05 2.87e+01 7.44e-01 9.89e+00 1353s
79 -2.46348056e+06 -4.20766591e+05 2.84e+01 7.43e-01 9.82e+00 1370s
80 -2.44563763e+06 -4.20462693e+05 2.82e+01 7.42e-01 9.77e+00 1387s
81 -2.40338790e+06 -4.09556693e+05 2.78e+01 7.30e-01 9.57e+00 1404s
82 -2.40337958e+06 -4.09537887e+05 2.78e+01 7.30e-01 9.57e+00 1421s
83 -2.40327229e+06 -4.09507703e+05 2.78e+01 7.30e-01 9.57e+00 1438s
84 -2.37564141e+06 -3.98120519e+05 2.75e+01 7.21e-01 9.42e+00 1454s
85 -2.32336000e+06 -3.79622950e+05 2.71e+01 7.09e-01 9.20e+00 1470s
86 -2.32327542e+06 -3.79596001e+05 2.71e+01 7.09e-01 9.20e+00 1486s
87 -2.31977989e+06 -3.78777766e+05 2.70e+01 7.08e-01 9.18e+00 1503s
88 -2.15466741e+06 -3.47562192e+05 2.54e+01 6.77e-01 8.56e+00 1520s
89 -2.15127581e+06 -3.41822874e+05 2.53e+01 6.71e-01 8.50e+00 1536s
90 -2.15134121e+06 -3.41851570e+05 2.53e+01 6.71e-01 8.50e+00 1553s
91 -2.14335907e+06 -3.28429645e+05 2.52e+01 6.59e-01 8.38e+00 1570s
92 -2.14332971e+06 -3.28418440e+05 2.52e+01 6.59e-01 8.38e+00 1586s
93 -2.14340283e+06 -3.28447718e+05 2.52e+01 6.59e-01 8.38e+00 1603s
94 -2.12446871e+06 -3.26303253e+05 2.50e+01 6.57e-01 8.32e+00 1620s
95 -2.12097513e+06 -3.25610031e+05 2.50e+01 6.56e-01 8.30e+00 1636s
96 -2.07242989e+06 -3.15183894e+05 2.45e+01 6.45e-01 8.11e+00 1653s
97 -2.07107577e+06 -3.13938753e+05 2.45e+01 6.44e-01 8.09e+00 1670s
98 -2.06415882e+06 -3.11963176e+05 2.44e+01 6.42e-01 8.06e+00 1687s
99 -2.06382595e+06 -3.11846647e+05 2.44e+01 6.42e-01 8.05e+00 1704s
100 -2.06320459e+06 -3.11758464e+05 2.44e+01 6.42e-01 8.05e+00 1721s
101 -2.06303559e+06 -3.11734356e+05 2.44e+01 6.41e-01 8.05e+00 1738s
102 -2.06251522e+06 -3.11652767e+05 2.44e+01 6.41e-01 8.05e+00 1756s
103 -2.06232646e+06 -3.11684840e+05 2.44e+01 6.41e-01 8.05e+00 1773s
104 -2.06219853e+06 -3.11638448e+05 2.44e+01 6.41e-01 8.05e+00 1791s
105 -2.06048889e+06 -3.11369199e+05 2.44e+01 6.41e-01 8.04e+00 1808s
106 -2.05935453e+06 -3.10543284e+05 2.44e+01 6.40e-01 8.03e+00 1826s
107 -2.05771976e+06 -3.10122332e+05 2.44e+01 6.40e-01 8.03e+00 1843s
108 -2.05532892e+06 -3.09211873e+05 2.43e+01 6.39e-01 8.01e+00 1862s
109 -2.05521170e+06 -3.09175282e+05 2.43e+01 6.39e-01 8.01e+00 1882s
110 -2.04880624e+06 -3.08132091e+05 2.43e+01 6.38e-01 7.99e+00 1899s
111 -2.04657729e+06 -3.07600552e+05 2.42e+01 6.37e-01 7.98e+00 1916s
112 -2.04658064e+06 -3.07601710e+05 2.42e+01 6.37e-01 7.98e+00 1933s
113 -2.04651589e+06 -3.07598513e+05 2.42e+01 6.37e-01 7.98e+00 1949s
114 -2.04653143e+06 -3.07604570e+05 2.42e+01 6.37e-01 7.98e+00 1966s
115 -2.04587714e+06 -3.07430562e+05 2.42e+01 6.37e-01 7.98e+00 1983s
116 -2.04319380e+06 -3.06168647e+05 2.42e+01 6.36e-01 7.96e+00 1999s
Barrier performed 116 iterations in 1998.90 seconds (3150.40 work units)
Numerical trouble encountered
Hmm, something went wrong!
ans =
'Numerical problems (learn to debug) (GUROBI)'Furthermore, considering the reproducibility of the results, I have uploaded the program and log that exceeds 400,000 seconds during the Crossover phase in MPS format to a sharing website: https://doi.org/10.5281/zenodo.13921293 . I hope you can access the file.
It should be noted that the uploaded file is an earlier version of the model and therefore does not correspond to the solver logs shown on the Gurobi community forum. The logs on the forum are from a model that has undergone parameter tuning, making it solvable with Crossover enabled. Given the age of the earlier version, it is difficult to trace back the exact parameter changes that made it solvable faster. However, I can confirm that the uploaded file reproduces the issue of the Crossover phase taking over 400,000 seconds.
I hope to receive further help from you and look forward to your valuable insights.
Best regards,
Zhongfan Gu
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