Source code for picos.expressions.cone_trivial

# 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
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# GNU General Public License for more details.
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"""Implements trivial cones."""

import operator
from collections import namedtuple

from .. import glyphs
from ..apidoc import api_end, api_start
from ..caching import cached_property
from ..constraints import (AffineConstraint, ComplexAffineConstraint,
                           DummyConstraint)
from .cone import Cone
from .exp_affine import AffineExpression, ComplexAffineExpression

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


[docs]class ZeroSpace(Cone): r"""The set containing zero."""
[docs] def __init__(self, dim=None): """Construct a :class:`ZeroSpace`.""" Cone.__init__(self, dim, "Zero Space", glyphs.set(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=True) elif issubclass(other.clstype, ComplexAffineExpression) \ and not subtype.dim or subtype.dim == other.subtype.dim: return ComplexAffineConstraint.make_type( dim=other.subtype.dim) return Cone._predict_base(cls, subtype, relation, other) def _rshift_implementation(self, element): if isinstance(element, ComplexAffineExpression): self._check_dimension(element) return element == 0 # Handle scenario uncertainty for all cones. return Cone._rshift_base(self, element) @cached_property def dual_cone(self): """Implement :attr:`.cone.Cone.dual_cone`.""" return TheField(dim=self.dim)
[docs]class TheField(Cone): r"""The real or complex field."""
[docs] def __init__(self, dim=None): """Construct a :class:`TheField`.""" Cone.__init__(self, dim, "The Field", "F")
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, ComplexAffineExpression) \ and not subtype.dim or subtype.dim == other.subtype.dim: return DummyConstraint.make_type() return Cone._predict_base(cls, subtype, relation, other) def _rshift_implementation(self, element): if isinstance(element, ComplexAffineExpression): self._check_dimension(element) return DummyConstraint(element) # Handle scenario uncertainty for all cones. return Cone._rshift_base(self, element) @cached_property def dual_cone(self): """Implement :attr:`.cone.Cone.dual_cone`.""" return ZeroSpace(dim=self.dim)
# -------------------------------------- __all__ = api_end(_API_START, globals())