+++ /dev/null
-import functools
-import numbers
-
-from . import islhelper
-
-from .islhelper import mainctx, libisl
-from .linexprs import Expression, Rational
-from .domains import Domain
-
-
-__all__ = [
- 'Polyhedron',
- 'Lt', 'Le', 'Eq', 'Ne', 'Ge', 'Gt',
- 'Empty', 'Universe',
-]
-
-
-class Polyhedron(Domain):
-
- __slots__ = (
- '_equalities',
- '_inequalities',
- '_constraints',
- '_symbols',
- '_dimension',
- )
-
- def __new__(cls, equalities=None, inequalities=None):
- if isinstance(equalities, str):
- if inequalities is not None:
- raise TypeError('too many arguments')
- return cls.fromstring(equalities)
- elif isinstance(equalities, Polyhedron):
- if inequalities is not None:
- raise TypeError('too many arguments')
- return equalities
- elif isinstance(equalities, Domain):
- if inequalities is not None:
- raise TypeError('too many arguments')
- return equalities.polyhedral_hull()
- if equalities is None:
- equalities = []
- else:
- for i, equality in enumerate(equalities):
- if not isinstance(equality, Expression):
- raise TypeError('equalities must be linear expressions')
- equalities[i] = equality.scaleint()
- if inequalities is None:
- inequalities = []
- else:
- for i, inequality in enumerate(inequalities):
- if not isinstance(inequality, Expression):
- raise TypeError('inequalities must be linear expressions')
- inequalities[i] = inequality.scaleint()
- symbols = cls._xsymbols(equalities + inequalities)
- islbset = cls._toislbasicset(equalities, inequalities, symbols)
- return cls._fromislbasicset(islbset, symbols)
-
- @property
- def equalities(self):
- return self._equalities
-
- @property
- def inequalities(self):
- return self._inequalities
-
- @property
- def constraints(self):
- return self._constraints
-
- @property
- def polyhedra(self):
- return self,
-
- def disjoint(self):
- return self
-
- def isuniverse(self):
- islbset = self._toislbasicset(self.equalities, self.inequalities,
- self.symbols)
- universe = bool(libisl.isl_basic_set_is_universe(islbset))
- libisl.isl_basic_set_free(islbset)
- return universe
-
- def polyhedral_hull(self):
- return self
-
- @classmethod
- def _fromislbasicset(cls, islbset, symbols):
- islconstraints = islhelper.isl_basic_set_constraints(islbset)
- equalities = []
- inequalities = []
- for islconstraint in islconstraints:
- constant = libisl.isl_constraint_get_constant_val(islconstraint)
- constant = islhelper.isl_val_to_int(constant)
- coefficients = {}
- for index, symbol in enumerate(symbols):
- coefficient = libisl.isl_constraint_get_coefficient_val(islconstraint,
- libisl.isl_dim_set, index)
- coefficient = islhelper.isl_val_to_int(coefficient)
- if coefficient != 0:
- coefficients[symbol] = coefficient
- expression = Expression(coefficients, constant)
- if libisl.isl_constraint_is_equality(islconstraint):
- equalities.append(expression)
- else:
- inequalities.append(expression)
- libisl.isl_basic_set_free(islbset)
- self = object().__new__(Polyhedron)
- self._equalities = tuple(equalities)
- self._inequalities = tuple(inequalities)
- self._constraints = tuple(equalities + inequalities)
- self._symbols = cls._xsymbols(self._constraints)
- self._dimension = len(self._symbols)
- return self
-
- @classmethod
- def _toislbasicset(cls, equalities, inequalities, symbols):
- dimension = len(symbols)
- indices = {symbol: index for index, symbol in enumerate(symbols)}
- islsp = libisl.isl_space_set_alloc(mainctx, 0, dimension)
- islbset = libisl.isl_basic_set_universe(libisl.isl_space_copy(islsp))
- islls = libisl.isl_local_space_from_space(islsp)
- for equality in equalities:
- isleq = libisl.isl_equality_alloc(libisl.isl_local_space_copy(islls))
- for symbol, coefficient in equality.coefficients():
- islval = str(coefficient).encode()
- islval = libisl.isl_val_read_from_str(mainctx, islval)
- index = indices[symbol]
- isleq = libisl.isl_constraint_set_coefficient_val(isleq,
- libisl.isl_dim_set, index, islval)
- if equality.constant != 0:
- islval = str(equality.constant).encode()
- islval = libisl.isl_val_read_from_str(mainctx, islval)
- isleq = libisl.isl_constraint_set_constant_val(isleq, islval)
- islbset = libisl.isl_basic_set_add_constraint(islbset, isleq)
- for inequality in inequalities:
- islin = libisl.isl_inequality_alloc(libisl.isl_local_space_copy(islls))
- for symbol, coefficient in inequality.coefficients():
- islval = str(coefficient).encode()
- islval = libisl.isl_val_read_from_str(mainctx, islval)
- index = indices[symbol]
- islin = libisl.isl_constraint_set_coefficient_val(islin,
- libisl.isl_dim_set, index, islval)
- if inequality.constant != 0:
- islval = str(inequality.constant).encode()
- islval = libisl.isl_val_read_from_str(mainctx, islval)
- islin = libisl.isl_constraint_set_constant_val(islin, islval)
- islbset = libisl.isl_basic_set_add_constraint(islbset, islin)
- return islbset
-
- @classmethod
- def fromstring(cls, string):
- domain = Domain.fromstring(string)
- if not isinstance(domain, Polyhedron):
- raise ValueError('non-polyhedral expression: {!r}'.format(string))
- return domain
-
- def __repr__(self):
- if self.isempty():
- return 'Empty'
- elif self.isuniverse():
- return 'Universe'
- else:
- strings = []
- for equality in self.equalities:
- strings.append('Eq({}, 0)'.format(equality))
- for inequality in self.inequalities:
- strings.append('Ge({}, 0)'.format(inequality))
- if len(strings) == 1:
- return strings[0]
- else:
- return 'And({})'.format(', '.join(strings))
-
- @classmethod
- def fromsympy(cls, expr):
- domain = Domain.fromsympy(expr)
- if not isinstance(domain, Polyhedron):
- raise ValueError('non-polyhedral expression: {!r}'.format(expr))
- return domain
-
- def tosympy(self):
- import sympy
- constraints = []
- for equality in self.equalities:
- constraints.append(sympy.Eq(equality.tosympy(), 0))
- for inequality in self.inequalities:
- constraints.append(sympy.Ge(inequality.tosympy(), 0))
- return sympy.And(*constraints)
-
-
-def _polymorphic(func):
- @functools.wraps(func)
- def wrapper(left, right):
- if isinstance(left, numbers.Rational):
- left = Rational(left)
- elif not isinstance(left, Expression):
- raise TypeError('left must be a a rational number '
- 'or a linear expression')
- if isinstance(right, numbers.Rational):
- right = Rational(right)
- elif not isinstance(right, Expression):
- raise TypeError('right must be a a rational number '
- 'or a linear expression')
- return func(left, right)
- return wrapper
-
-@_polymorphic
-def Lt(left, right):
- return Polyhedron([], [right - left - 1])
-
-@_polymorphic
-def Le(left, right):
- return Polyhedron([], [right - left])
-
-@_polymorphic
-def Eq(left, right):
- return Polyhedron([left - right], [])
-
-@_polymorphic
-def Ne(left, right):
- return ~Eq(left, right)
-
-@_polymorphic
-def Gt(left, right):
- return Polyhedron([], [left - right - 1])
-
-@_polymorphic
-def Ge(left, right):
- return Polyhedron([], [left - right])
-
-
-Empty = Eq(1, 0)
-
-Universe = Polyhedron([])
projects / linpy.git / blobdiff