Source code for picos.solvers.solver_smcp

# ------------------------------------------------------------------------------
# Copyright (C) 2017 Maximilian Stahlberg
#
# This file is part of PICOS.
#
# PICOS is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# PICOS is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# this program.  If not, see <http://www.gnu.org/licenses/>.
# ------------------------------------------------------------------------------

"""Implementation of :class:`SMCPSolver`."""

# ------------------------------------------------------------------------------
# This file is a skeleton implementation for the SMCP solver.
# Currently, the functional implementation is found in CVXOPTSolver.
# ------------------------------------------------------------------------------

from ..apidoc import api_end, api_start
from ..constraints import AffineConstraint, DummyConstraint, LMIConstraint
from ..expressions import CONTINUOUS_VARTYPES, AffineExpression
from ..modeling.footprint import Specification
from .solver import Solver
from .solver_cvxopt import CVXOPTSolver

_API_START = api_start(globals())
# -------------------------------


[docs]class SMCPSolver(CVXOPTSolver): """Interface to the SMCP solver. Most of the logic is implemented in the :class:`CVXOPTSolver <picos.solvers.solver_cvxopt.CVXOPTSolver>` base class. """ SUPPORTED = Specification( objectives=[ AffineExpression], variables=CONTINUOUS_VARTYPES, constraints=[ DummyConstraint, AffineConstraint, # TODO: See below. # SOCConstraint, # RSOCConstraint, LMIConstraint])
[docs] @classmethod def supports(cls, footprint, explain=False): """Implement :meth:`~.solver.Solver.supports`.""" result = Solver.supports(footprint, explain) if not result or (explain and not result[0]): return result # TODO: SMCP formally supports problems that are not SDPs, but it is # known to perform poorly for them, sometimes even returning # incorrect solutions. For now, only support SDPs. if not ("con", LMIConstraint) in footprint: if explain: return False, "Problems other than SDPs (PICOS' choice)." else: return False if footprint not in cls.SUPPORTED: if explain: return False, cls.SUPPORTED.mismatch_reason(footprint) else: return False return (True, None) if explain else True
[docs] @classmethod def default_penalty(cls): """Implement :meth:`~.solver.Solver.default_penalty`.""" return 2.0 # Experimental free/open source solver.
[docs] @classmethod def test_availability(cls): """Implement :meth:`~.solver.Solver.test_availability`.""" cls.check_import("smcp")
[docs] @classmethod def names(cls): """Implement :meth:`~.solver.Solver.names`.""" return "smcp", "SMCP", "Sparse Matrix Cone Program Solver"
[docs] @classmethod def is_free(cls): """Implement :meth:`~.solver.Solver.is_free`.""" return True
@property def is_smcp(self): """Whether to implement SMCP instead of CVXOPT.""" return True
# -------------------------------------- __all__ = api_end(_API_START, globals())