CPLEX example¶
[1]:
from optiwindnet.importer import load_repository
from optiwindnet.svg import svgplot
from optiwindnet.mesh import make_planar_embedding
from optiwindnet.interarraylib import G_from_S
from optiwindnet.heuristics import EW_presolver
from optiwindnet.MILP import solver_factory, ModelOptions
Initialize Race Bank 2¶
[2]:
locations = load_repository()
[3]:
L = locations.race
capacity = 5
[4]:
svgplot(L)
[4]:
Optimize Race Bank 2¶
[5]:
P, A = make_planar_embedding(L)
Initial heuristic solution to warm-start the solver:
[6]:
Sʹ = EW_presolver(A, capacity=capacity)
Gʹ = G_from_S(Sʹ, A)
svgplot(Gʹ)
[6]:
[7]:
solver = solver_factory('cplex')
[8]:
solver.set_problem(
P, A,
capacity=Sʹ.graph['capacity'],
model_options=ModelOptions(
topology="branched",
feeder_route="segmented",
feeder_limit="unlimited",
),
warmstart=Sʹ,
)
[9]:
solver.solve(
mip_gap=0.002,
time_limit=20,
verbose=True,
)
Version identifier: 22.1.2.0 | 2024-11-25 | 0edbb82fd
CPXPARAM_Read_DataCheck 1
CPXPARAM_Parallel -1
CPXPARAM_Emphasis_MIP 4
CPXPARAM_TimeLimit 20
CPXPARAM_MIP_Tolerances_MIPGap 0.002
1 of 1 MIP starts provided solutions.
MIP start 'm1' defined initial solution with objective 93274.5215.
Tried aggregator 1 time.
MIP Presolve eliminated 368 rows and 0 columns.
MIP Presolve modified 1040 coefficients.
Reduced MIP has 2740 rows, 2080 columns, and 9890 nonzeros.
Reduced MIP has 1040 binaries, 1040 generals, 0 SOSs, and 0 indicators.
Presolve time = 0.00 sec. (7.87 ticks)
Probing time = 0.01 sec. (2.90 ticks)
Tried aggregator 1 time.
Detecting symmetries...
Reduced MIP has 2740 rows, 2080 columns, and 9890 nonzeros.
Reduced MIP has 1040 binaries, 1040 generals, 0 SOSs, and 0 indicators.
Presolve time = 0.00 sec. (6.22 ticks)
Probing time = 0.02 sec. (2.83 ticks)
Clique table members: 476.
MIP emphasis: hidden feasible solutions.
MIP search method: dynamic search.
Parallel mode: opportunistic, using up to 16 threads.
Root relaxation solution time = 0.03 sec. (36.66 ticks)
Nodes Cuts/
Node Left Objective IInf Best Integer Best Bound ItCnt Gap
* 0+ 0 93274.5215 0.0000 100.00%
0 0 85779.2773 106 93274.5215 85779.2773 1392 8.04%
* 0+ 0 91529.1336 85779.2773 6.28%
0 0 86296.5926 291 91529.1336 Cuts: 112 1615 5.72%
0 0 86449.7008 233 91529.1336 Cuts: 113 1773 5.55%
* 0+ 0 90212.0836 86449.7008 4.17%
0 0 86530.8140 310 90212.0836 Cuts: 44 1854 4.08%
0 0 86591.5711 260 90212.0836 Cuts: 45 1935 4.01%
0 0 86613.4710 293 90212.0836 Cuts: 25 2000 3.99%
Detecting symmetries...
0 0 86630.5237 312 90212.0836 Cuts: 27 2054 3.97%
* 0+ 0 89811.3539 86630.5237 3.54%
0 0 86656.5904 314 89811.3539 Cuts: 26 2131 3.51%
0 0 86668.0809 308 89811.3539 Cuts: 23 2187 3.50%
* 0+ 0 88489.5866 86668.0809 2.06%
0 0 -1.00000e+75 0 88489.5866 86668.0809 2187 2.06%
0 0 86688.9715 323 88489.5866 Cuts: 29 2250 2.03%
0 0 86728.0362 292 88489.5866 Cuts: 13 2310 1.99%
0 0 86743.6061 316 88489.5866 Cuts: 25 2380 1.97%
0 0 86755.7227 324 88489.5866 Cuts: 31 2446 1.96%
0 0 86758.6886 318 88489.5866 Cuts: 21 2468 1.96%
0 0 86761.2511 312 88489.5866 Cuts: 19 2495 1.95%
* 0+ 0 88420.3525 86761.2511 1.88%
* 0+ 0 88331.6140 86761.2511 1.78%
0 0 -1.00000e+75 0 88331.6140 86761.2511 2495 1.78%
Detecting symmetries...
0 2 86761.2511 312 88331.6140 86761.2511 2495 1.78%
Elapsed time = 2.92 sec. (1626.09 ticks, tree = 0.02 MB, solutions = 7)
219 169 86992.6114 291 88331.6140 86797.0783 28596 1.74%
552 393 87304.9614 263 88331.6140 86797.0783 62224 1.74%
952 567 87938.1457 193 88331.6140 86895.1664 83205 1.63%
* 1398+ 807 88167.0731 86946.6821 1.38%
1453 935 87450.9176 219 88167.0731 86946.6821 123491 1.38%
* 1792+ 1113 87993.7803 86958.9363 1.18%
1853 1135 cutoff 87993.7803 86958.9363 155644 1.18%
2219 1129 87094.4152 312 87993.7803 87006.4361 182773 1.12%
2709 1512 87584.8536 287 87993.7803 87067.9193 238180 1.05%
3129 1670 87323.2703 249 87993.7803 87082.0990 255155 1.04%
3508 1970 87973.1209 233 87993.7803 87082.0990 288727 1.04%
* 4582+ 2467 87938.3833 87144.1873 0.90%
Performing restart 1
Repeating presolve.
Tried aggregator 2 times.
MIP Presolve eliminated 381 rows and 350 columns.
MIP Presolve modified 135 coefficients.
Aggregator did 2 substitutions.
Reduced MIP has 2357 rows, 1728 columns, and 8268 nonzeros.
Reduced MIP has 868 binaries, 860 generals, 0 SOSs, and 0 indicators.
Presolve time = 0.01 sec. (6.21 ticks)
Tried aggregator 1 time.
Reduced MIP has 2357 rows, 1728 columns, and 8268 nonzeros.
Reduced MIP has 868 binaries, 860 generals, 0 SOSs, and 0 indicators.
Presolve time = 0.00 sec. (5.54 ticks)
Represolve time = 0.05 sec. (28.48 ticks)
4589 0 86847.0677 351 87938.3833 Cuts: 116 394059 0.88%
4589 0 86872.8665 342 87938.3833 Cuts: 65 394171 0.88%
* 4589+ 0 87802.9883 87162.8768 0.73%
4589 0 86892.1240 363 87802.9883 Cuts: 100 394292 0.73%
4589 0 86908.8440 365 87802.9883 Cuts: 81 394425 0.73%
4589 0 86925.2403 374 87802.9883 Cuts: 105 394559 0.73%
4589 0 86935.4419 375 87802.9883 Cuts: 68 394680 0.73%
4589 16 cutoff 87802.9883 87222.3496 399510 0.66%
Elapsed time = 11.91 sec. (6659.73 ticks, tree = 0.02 MB, solutions = 12)
4940 13 87517.9866 370 87802.9883 87233.7246 397451 0.65%
5074 28 cutoff 87802.9883 87233.7246 402592 0.65%
GUB cover cuts applied: 6
Cover cuts applied: 1
Flow cuts applied: 44
Mixed integer rounding cuts applied: 105
Zero-half cuts applied: 47
Lift and project cuts applied: 62
Gomory fractional cuts applied: 5
Root node processing (before b&c):
Real time = 2.80 sec. (1624.64 ticks)
Parallel b&c, 16 threads:
Real time = 10.25 sec. (7660.06 ticks)
Sync time (average) = 1.63 sec.
Wait time (average) = 0.01 sec.
------------
Total (root+branch&cut) = 13.05 sec. (9284.70 ticks)
[9]:
SolutionInfo(runtime=13.05971646308899, bound=87628.45738695332, objective=87802.98827587758, relgap=0.001987755682937409, termination='optimal')
[10]:
S, G = solver.get_solution()
[11]:
svgplot(G)
[11]:
