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"""Implementation of :class:`ExpressionDomain` 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.core import sympify, SympifyError from sympy.utilities import public from sympy.polys.polyutils import PicklableWithSlots
@public class ExpressionDomain(Field, CharacteristicZero, SimpleDomain): """A class for arbitrary expressions. """
is_SymbolicDomain = is_EX = True
class Expression(PicklableWithSlots): """An arbitrary expression. """
__slots__ = ['ex']
def __init__(self, ex): else:
def __repr__(f): return 'EX(%s)' % repr(f.ex)
def __str__(f): return 'EX(%s)' % str(f.ex)
def __hash__(self):
def as_expr(f):
def numer(f): return f.__class__(f.ex.as_numer_denom()[0])
def denom(f):
def simplify(f, ex):
def __abs__(f): return f.__class__(abs(f.ex))
def __neg__(f): return f.__class__(-f.ex)
def _to_ex(f, g): except SympifyError: return None
def __add__(f, g): g = f._to_ex(g)
if g is not None: return f.simplify(f.ex + g.ex) else: return NotImplemented
def __radd__(f, g): return f.simplify(f.__class__(g).ex + f.ex)
def __sub__(f, g): g = f._to_ex(g)
if g is not None: return f.simplify(f.ex - g.ex) else: return NotImplemented
def __rsub__(f, g): return f.simplify(f.__class__(g).ex - f.ex)
def __mul__(f, g):
else: return NotImplemented
def __rmul__(f, g): return f.simplify(f.__class__(g).ex*f.ex)
def __pow__(f, n): n = f._to_ex(n)
if n is not None: return f.simplify(f.ex**n.ex) else: return NotImplemented
def __truediv__(f, g):
else: return NotImplemented
def __rtruediv__(f, g): return f.simplify(f.__class__(g).ex/f.ex)
__div__ = __truediv__ __rdiv__ = __rtruediv__
def __eq__(f, g):
def __ne__(f, g): return not f.__eq__(g)
def __nonzero__(f):
__bool__ = __nonzero__
def gcd(f, g):
def lcm(f, g):
dtype = Expression
zero = Expression(0) one = Expression(1)
rep = 'EX'
has_assoc_Ring = False has_assoc_Field = True
def __init__(self): pass
def to_sympy(self, a): """Convert ``a`` to a SymPy object. """
def from_sympy(self, a): """Convert SymPy's expression to ``dtype``. """
def from_ZZ_python(K1, a, K0): """Convert a Python ``int`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_QQ_python(K1, a, K0): """Convert a Python ``Fraction`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_ZZ_gmpy(K1, a, K0): """Convert a GMPY ``mpz`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_QQ_gmpy(K1, a, K0): """Convert a GMPY ``mpq`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_RealField(K1, a, K0): """Convert a mpmath ``mpf`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_PolynomialRing(K1, a, K0): """Convert a ``DMP`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_FractionField(K1, a, K0): """Convert a ``DMF`` object to ``dtype``. """ return K1(K0.to_sympy(a))
def from_ExpressionDomain(K1, a, K0): """Convert a ``EX`` object to ``dtype``. """ return a
def get_ring(self): """Returns a ring associated with ``self``. """ return self # XXX: EX is not a ring but we don't have much choice here.
def get_field(self): """Returns a field associated with ``self``. """
def is_positive(self, a): """Returns True if ``a`` is positive. """ return a.ex.as_coeff_mul()[0].is_positive
def is_negative(self, a): """Returns True if ``a`` is negative. """ return a.ex.as_coeff_mul()[0].is_negative
def is_nonpositive(self, a): """Returns True if ``a`` is non-positive. """ return a.ex.as_coeff_mul()[0].is_nonpositive
def is_nonnegative(self, a): """Returns True if ``a`` is non-negative. """ return a.ex.as_coeff_mul()[0].is_nonnegative
def numer(self, a): """Returns numerator of ``a``. """ return a.numer()
def denom(self, a): """Returns denominator of ``a``. """
def gcd(self, a, b):
def lcm(self, a, b): |