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87 lines
2.8 KiB
87 lines
2.8 KiB
# MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
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# Copyright (C) 2020-2022, UChicago Argonne, LLC. All rights reserved.
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# Released under the modified BSD license. See COPYING.md for more details.
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import json
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import os
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from io import StringIO
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from os.path import exists
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from typing import Callable, List
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from ..h5 import H5File
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from ..io import _RedirectOutput, gzip, _to_h5_filename
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from ..parallel import p_umap
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class BasicCollector:
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def collect(
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self,
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filenames: List[str],
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build_model: Callable,
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n_jobs: int = 1,
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progress: bool = False,
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) -> None:
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def _collect(data_filename):
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h5_filename = _to_h5_filename(data_filename)
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mps_filename = h5_filename.replace(".h5", ".mps")
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if exists(h5_filename):
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# Try to read optimal solution
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mip_var_values = None
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try:
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with H5File(h5_filename, "r") as h5:
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mip_var_values = h5.get_array("mip_var_values")
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except:
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pass
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if mip_var_values is None:
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print(f"Removing empty/corrupted h5 file: {h5_filename}")
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os.remove(h5_filename)
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else:
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return
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with H5File(h5_filename, "w") as h5:
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streams = [StringIO()]
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with _RedirectOutput(streams):
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# Load and extract static features
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model = build_model(data_filename)
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model.extract_after_load(h5)
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# Solve LP relaxation
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relaxed = model.relax()
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relaxed.optimize()
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relaxed.extract_after_lp(h5)
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# Solve MIP
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model.optimize()
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model.extract_after_mip(h5)
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# Add lazy constraints to model
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if (
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hasattr(model, "fix_violations")
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and model.fix_violations is not None
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):
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model.fix_violations(model, model.violations_, "aot")
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h5.put_scalar(
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"mip_constr_violations", json.dumps(model.violations_)
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)
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# Save MPS file
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model.write(mps_filename)
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gzip(mps_filename)
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h5.put_scalar("mip_log", streams[0].getvalue())
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if n_jobs > 1:
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p_umap(
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_collect,
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filenames,
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num_cpus=n_jobs,
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desc="collect",
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smoothing=0,
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disable=not progress,
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)
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else:
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for filename in filenames:
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_collect(filename)
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