def _eval_power(self, other, terms=False):
# n n n
# (-3 + y) -> (-1) * (3 - y)
#
# If terms=True then return the arguments that should be
# multiplied together rather than multiplying them.
#
# At present, as_coeff_terms return +/-1 but the
# following should work even if that changes.
if Basic.keep_sign:
return None
rv = None
c, t = self.as_coeff_mul()
if c.is_negative and not other.is_integer:
if c is not S.NegativeOne and self.is_positive:
coeff = C.Pow(-c, other)
assert len(t) == 1, 't'
b = -t[0]
rv = (coeff, C.Pow(b, other))
elif c is not S.One:
coeff = C.Pow(c, other)
assert len(t) == 1, 't'
b = t[0]
rv = (coeff, C.Pow(b, other))
if not rv or terms:
return rv
else:
return C.Mul(*rv)
def _create_evalf_table():
global evalf_table
evalf_table = {
C.Symbol: evalf_symbol,
C.Dummy: evalf_symbol,
C.Float: lambda x, prec, options: (x._mpf_, None, prec, None),
C.Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None),
C.Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None),
C.Zero: lambda x, prec, options: (None, None, prec, None),
C.One: lambda x, prec, options: (fone, None, prec, None),
C.Half: lambda x, prec, options: (fhalf, None, prec, None),
C.Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None),
C.Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None),
C.ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec),
C.NegativeOne: lambda x, prec, options: (fnone, None, prec, None),
C.NaN : lambda x, prec, options: (fnan, None, prec, None),
C.exp: lambda x, prec, options: evalf_pow(C.Pow(S.Exp1, x.args[0],
evaluate=False), prec, options),
C.cos: evalf_trig,
C.sin: evalf_trig,
C.Add: evalf_add,
C.Mul: evalf_mul,
C.Pow: evalf_pow,
C.log: evalf_log,
C.atan: evalf_atan,
C.Abs: evalf_abs,
C.re: evalf_re,
C.im: evalf_im,
C.floor: evalf_floor,
C.ceiling: evalf_ceiling,
C.Integral: evalf_integral,
C.Sum: evalf_sum,
C.Piecewise: evalf_piecewise,
C.bernoulli: evalf_bernoulli,
}