Source code for picos.expressions.cone_nno

# coding: utf-8

# ------------------------------------------------------------------------------
# Copyright (C) 2020 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.
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# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
# ------------------------------------------------------------------------------

"""Implements the nonnegative orthant cone."""

import operator
from collections import namedtuple

from .. import glyphs
from ..apidoc import api_end, api_start
from ..constraints import AffineConstraint
from ..constraints.uncertain import ConicallyUncertainAffineConstraint
from .cone import Cone
from .exp_affine import AffineExpression
from .uncertain.pert_conic import ConicPerturbationSet
from .uncertain.uexp_affine import UncertainAffineExpression

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


[docs]class NonnegativeOrthant(Cone): """The nonnegative orthant."""
[docs] def __init__(self, dim=None): """Construct a :class:`NonnegativeOrthant`.""" Cone.__init__(self, dim, "Nonnegative Orthant", glyphs.set(glyphs.ge("x", glyphs.scalar(0))))
def _get_mutables(self): return frozenset() def _replace_mutables(self): return self Subtype = namedtuple("Subtype", ("dim",)) def _get_subtype(self): return self.Subtype(self.dim) @classmethod def _predict(cls, subtype, relation, other): assert isinstance(subtype, cls.Subtype) if relation == operator.__rshift__: if issubclass(other.clstype, AffineExpression) \ and not subtype.dim or subtype.dim == other.subtype.dim: return AffineConstraint.make_type( dim=other.subtype.dim, eq=False) elif issubclass(other.clstype, UncertainAffineExpression) \ and not subtype.dim or subtype.dim == other.subtype.dim: universe = other.subtype.universe_type if issubclass(universe.clstype, ConicPerturbationSet): return ConicallyUncertainAffineConstraint.make_type( dim=other.subtype.dim, universe_subtype=universe.subtype) return Cone._predict_base(cls, subtype, relation, other) def _rshift_implementation(self, element): if isinstance(element, AffineExpression): self._check_dimension(element) return element >= 0 elif isinstance(element, UncertainAffineExpression): self._check_dimension(element) if isinstance(element.universe, ConicPerturbationSet): return ConicallyUncertainAffineConstraint(-element) # Handle scenario uncertainty for all cones. return Cone._rshift_base(self, element) @property def dual_cone(self): """Implement :attr:`.cone.Cone.dual_cone`.""" return self
# -------------------------------------- __all__ = api_end(_API_START, globals())