def _eval_power(b, e):
"""
b is Real but not equal to rationals, integers, 0.5, oo, -oo, nan
e is symbolic object but not equal to 0, 1
(-p) ** r -> exp(r * log(-p)) -> exp(r * (log(p) + I*Pi)) ->
-> p ** r * (sin(Pi*r) + cos(Pi*r) * I)
"""
if isinstance(e, Number):
if isinstance(e, Integer):
e = e.p
return Real(decimal_math.pow(b.num, e))
e2 = e._as_decimal()
if b.is_negative and not e.is_integer:
m = decimal_math.pow(-b.num, e2)
a = decimal_math.pi() * e2
s = m * decimal_math.sin(a)
c = m * decimal_math.cos(a)
return Real(s) + Real(c) * S.ImaginaryUnit
return Real(decimal_math.pow(b.num, e2))
return
def _eval_power(b, e):
if e.is_odd: return S.NegativeOne
if e.is_even: return S.One
if isinstance(e, Number):
if isinstance(e, Real):
a = e.num * decimal_math.pi()
s = decimal_math.sin(a)
c = decimal_math.cos(a)
return Real(s) + Real(c) * S.ImaginaryUnit
if isinstance(e, NaN):
return S.NaN
if isinstance(e, (Infinity, NegativeInfinity)):
return S.NaN
if isinstance(e, Half):
return S.ImaginaryUnit
if isinstance(e, Rational):
if e.q == 2:
return S.ImaginaryUnit ** Integer(e.p)
q = int(e)
if q:
q = Integer(q)
return b ** q * b ** (e - q)
return
t.lexer.skip(1)
# Build the lexer
lex.lex()
# Parsing rules
precedence = (
('left','PLUS','MINUS'),
('left','TIMES','DIVIDE'),
('right','UMINUS'),
('right','RAISE_TO'),
)
names = {'e': exp(Decimal(1)), 'pi': pi(), '_last': Decimal(0)}
reserved_names = ['e','pi','_last']
def p_statement_assign(t):
'statement : NAME EQUALS expression'
if t[1] in reserved_names:
print "Name %s reserved" % t[1]
else:
names[t[1]] = t[3]
def p_set_last_to(t):
'statement : SET_TO NAME'
if t[2] in reserved_names:
print "Name %s reserved" % t[2]
else:
names[t[2]] = names['_last']
def _eval_evalf(self):
return Real(decimal_math.pi())
t.lexer.skip(1)
# Build the lexer
lex.lex()
# Parsing rules
precedence = (
('left', 'PLUS', 'MINUS'),
('left', 'TIMES', 'DIVIDE'),
('right', 'UMINUS'),
('right', 'RAISE_TO'),
)
names = {'e': exp(Decimal(1)), 'pi': pi(), '_last': Decimal(0)}
reserved_names = ['e', 'pi', '_last']
def p_statement_assign(t):
'statement : NAME EQUALS expression'
if t[1] in reserved_names:
print "Name %s reserved" % t[1]
else:
names[t[1]] = t[3]
def p_set_last_to(t):
'statement : SET_TO NAME'
if t[2] in reserved_names:
print "Name %s reserved" % t[2]
