Source code for sympy.polys.domains.algebraicfield

"""Implementation of :class:`AlgebraicField` class. """

from __future__ import print_function, division

from sympy.polys.domains.field import Field
from sympy.polys.domains.simpledomain import SimpleDomain
from sympy.polys.domains.characteristiczero import CharacteristicZero

from sympy.polys.polyclasses import ANP
from sympy.polys.polyerrors import CoercionFailed, DomainError, NotAlgebraic, IsomorphismFailed

from sympy.utilities import public

@public
[docs]class AlgebraicField(Field, CharacteristicZero, SimpleDomain): """A class for representing algebraic number fields. """ dtype = ANP is_AlgebraicField = is_Algebraic = True is_Numerical = True has_assoc_Ring = False has_assoc_Field = True def __init__(self, dom, *ext): if not dom.is_QQ: raise DomainError("ground domain must be a rational field") from sympy.polys.numberfields import to_number_field self.orig_ext = ext self.ext = to_number_field(ext) self.mod = self.ext.minpoly.rep self.domain = self.dom = dom self.ngens = 1 self.symbols = self.gens = (self.ext,) self.unit = self([dom(1), dom(0)]) self.zero = self.dtype.zero(self.mod.rep, dom) self.one = self.dtype.one(self.mod.rep, dom) def new(self, element): return self.dtype(element, self.mod.rep, self.dom) def __str__(self): return str(self.dom) + '<' + str(self.ext) + '>' def __hash__(self): return hash((self.__class__.__name__, self.dtype, self.dom, self.ext)) def __eq__(self, other): """Returns ``True`` if two domains are equivalent. """ return isinstance(other, AlgebraicField) and \ self.dtype == other.dtype and self.ext == other.ext
[docs] def algebraic_field(self, *extension): r"""Returns an algebraic field, i.e. `\mathbb{Q}(\alpha, \ldots)`. """ return AlgebraicField(self.dom, *((self.ext,) + extension))
[docs] def to_sympy(self, a): """Convert ``a`` to a SymPy object. """ from sympy.polys.numberfields import AlgebraicNumber return AlgebraicNumber(self.ext, a).as_expr()
[docs] def from_sympy(self, a): """Convert SymPy's expression to ``dtype``. """ try: return self([self.dom.from_sympy(a)]) except CoercionFailed: pass from sympy.polys.numberfields import to_number_field try: return self(to_number_field(a, self.ext).native_coeffs()) except (NotAlgebraic, IsomorphismFailed): raise CoercionFailed( "%s is not a valid algebraic number in %s" % (a, self))
[docs] def from_ZZ_python(K1, a, K0): """Convert a Python ``int`` object to ``dtype``. """ return K1(K1.dom.convert(a, K0))
[docs] def from_QQ_python(K1, a, K0): """Convert a Python ``Fraction`` object to ``dtype``. """ return K1(K1.dom.convert(a, K0))
[docs] def from_ZZ_gmpy(K1, a, K0): """Convert a GMPY ``mpz`` object to ``dtype``. """ return K1(K1.dom.convert(a, K0))
[docs] def from_QQ_gmpy(K1, a, K0): """Convert a GMPY ``mpq`` object to ``dtype``. """ return K1(K1.dom.convert(a, K0))
[docs] def from_RealField(K1, a, K0): """Convert a mpmath ``mpf`` object to ``dtype``. """ return K1(K1.dom.convert(a, K0))
[docs] def get_ring(self): """Returns a ring associated with ``self``. """ raise DomainError('there is no ring associated with %s' % self)
[docs] def is_positive(self, a): """Returns True if ``a`` is positive. """ return self.dom.is_positive(a.LC())
[docs] def is_negative(self, a): """Returns True if ``a`` is negative. """ return self.dom.is_negative(a.LC())
[docs] def is_nonpositive(self, a): """Returns True if ``a`` is non-positive. """ return self.dom.is_nonpositive(a.LC())
[docs] def is_nonnegative(self, a): """Returns True if ``a`` is non-negative. """ return self.dom.is_nonnegative(a.LC())
[docs] def numer(self, a): """Returns numerator of ``a``. """ return a
[docs] def denom(self, a): """Returns denominator of ``a``. """ return self.one