No behaviour has changed, except for:
- Real ** Even does not always get symplified by refine() to abs(Real) **
Even,
only in the case of nested powers. This is now the same behaviour as
Mathematica.
Relevant tests moved to queries/test/test_queries.py and
refine/tests/test_refine.py
---
sympy/core/add.py | 7 --
sympy/core/mul.py | 28 +-----
sympy/core/numbers.py | 23 ++---
sympy/core/power.py | 9 --
sympy/core/tests/test_arit.py | 110 --------------------
sympy/core/tests/test_eval_power.py | 8 --
sympy/core/tests/test_numbers.py | 3 +-
sympy/functions/elementary/exponential.py | 19 ++--
.../functions/elementary/tests/test_exponential.py | 5 -
9 files changed, 18 insertions(+), 194 deletions(-)
diff --git a/sympy/core/add.py b/sympy/core/add.py
index 69ec473..917218a 100644
--- a/sympy/core/add.py
+++ b/sympy/core/add.py
@@ -234,13 +234,6 @@ def _eval_is_polynomial(self, syms):
_eval_is_integer = lambda self: self._eval_template_is_attr('is_integer')
_eval_is_comparable = lambda self:
self._eval_template_is_attr('is_comparable')
- def _eval_is_odd(self):
- l = [f for f in self.args if not (f.is_even==True)]
- if not l:
- return False
- if l[0].is_odd:
- return Add(*l[1:]).is_even
-
def _eval_is_irrational(self):
for t in self.args:
a = t.is_irrational
diff --git a/sympy/core/mul.py b/sympy/core/mul.py
index 6af50b3..27279e0 100644
--- a/sympy/core/mul.py
+++ b/sympy/core/mul.py
@@ -339,7 +339,7 @@ def _eval_power(b, e):
return coeff**e * Mul(*l)
c,t = b.as_coeff_terms()
- if e.is_even and c.is_Number and c < 0:
+ if e.is_Number and (e % 2 == 0) and c.is_Number and c < 0:
return (-c * Mul(*t)) ** e
#if e.atoms(Wild):
@@ -681,32 +681,6 @@ def _eval_is_negative(self):
if c.is_nonnegative and r.is_nonnegative:
return False
- def _eval_is_odd(self):
- is_integer = self.is_integer
-
- if is_integer:
- r = True
- for t in self.args:
- if t.is_even:
- return False
- if t.is_odd is None:
- r = None
- return r
-
- # !integer -> !odd
- elif is_integer == False:
- return False
-
-
- def _eval_is_even(self):
- is_integer = self.is_integer
-
- if is_integer:
- return fuzzy_not(self._eval_is_odd())
-
- elif is_integer == False:
- return False
-
def _eval_subs(self, old, new):
if self == old:
return new
diff --git a/sympy/core/numbers.py b/sympy/core/numbers.py
index 59e86e5..8940f57 100644
--- a/sympy/core/numbers.py
+++ b/sympy/core/numbers.py
@@ -606,11 +606,6 @@ def _eval_power(b, e):
else:
return (-1)**e * (-b)**e
- c,t = b.as_coeff_terms()
- if e.is_even and isinstance(c, Number) and c < 0:
- return (-c * Mul(*t)) ** e
-
- return
def _as_mpf_val(self, prec):
return mlib.from_rational(self.p, self.q, prec, rnd)
@@ -932,12 +927,6 @@ def _eval_power(base, exp):
if base.p == -1: return S.NaN
# cases 0, 1 are done in their respective classes
return S.Infinity + S.ImaginaryUnit * S.Infinity
- if not isinstance(exp, Number):
- # simplify when exp is even
- # (-2) ** k --> 2 ** k
- c,t = base.as_coeff_terms()
- if exp.is_even and isinstance(c, Number) and c < 0:
- return (-c * Mul(*t)) ** exp
if not isinstance(exp, Rational): return
if exp is S.Half and base < 0:
# we extract I for this special case since everyone is doing so
@@ -1090,18 +1079,20 @@ def __neg__():
return S.One
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):
+ if e.is_Number:
+ if e.is_Real:
return Real(-1.0) ** e
+ if e.is_Integer:
+ if e % 2:
+ return S.NegativeOne
+ else: return S.One
if e is S.NaN:
return S.NaN
if e is S.Infinity or e is S.NegativeInfinity:
return S.NaN
if e is S.Half:
return S.ImaginaryUnit
- if isinstance(e, Rational):
+ if e.is_Rational:
if e.q == 2:
return S.ImaginaryUnit ** Integer(e.p)
q = int(e)
diff --git a/sympy/core/power.py b/sympy/core/power.py
index 79e29f8..a485274 100644
--- a/sympy/core/power.py
+++ b/sympy/core/power.py
@@ -98,8 +98,6 @@ def _eval_power(self, other):
return Pow(self.base, self.exp * other)
if self.base.is_nonnegative and self.exp.is_real and other.is_real:
return Pow(self.base, self.exp * other)
- if self.exp.is_even and self.base.is_real:
- return Pow(abs(self.base), self.exp * other)
if self.exp.is_real and other.is_real and abs(self.exp) < S.One:
return Pow(self.base, self.exp * other)
return
@@ -111,13 +109,6 @@ def _eval_is_comparable(self):
if c2 is None: return
return c1 and c2
- def _eval_is_even(self):
- if self.exp.is_integer and self.exp.is_positive:
- if self.base.is_even:
- return True
- if self.base.is_integer:
- return False
-
def _eval_is_positive(self):
if self.base.is_positive:
if self.exp.is_real:
diff --git a/sympy/core/tests/test_arit.py b/sympy/core/tests/test_arit.py
index 3a94bb3..9bd5ec1 100644
--- a/sympy/core/tests/test_arit.py
+++ b/sympy/core/tests/test_arit.py
@@ -138,14 +138,6 @@ def test_pow():
assert (x**(y**(x+exp(x+y))+z)).expand(deep=False) == x**z*x**(y**(x +
exp(x + y)))
assert (x**(y**(x+exp(x+y))+z)).expand() ==
x**z*x**(y**x*y**(exp(x)*exp(y)))
- n = Symbol('k', even=False)
- k = Symbol('k', even=True)
-
- assert (-1)**x == (-1)**x
- assert (-1)**n == (-1)**n
- assert (-2)**k == 2**k
- assert (-1)**k == 1
-
@XFAIL
def test_pow2():
# XXX These fail - they are maybe discutable,
@@ -308,77 +300,6 @@ def test_Add_Mul_is_bounded():
assert (sin(x)-67).is_bounded == True
assert (sin(x)+exp(x)).is_bounded == False
-def test_Mul_is_even_odd():
- x = Symbol('x', integer=True)
-
- k = Symbol('k', odd=True)
- n = Symbol('n', odd=True)
- m = Symbol('m', even=True)
-
- assert (2*x).is_even == True
- assert (2*x).is_odd == False
-
- assert (3*x).is_even == None
- assert (3*x).is_odd == None
-
- assert (k/3).is_integer == False
- assert (k/3).is_even == False
- assert (k/3).is_odd == False
-
- assert (2*n).is_even == True
- assert (2*n).is_odd == False
-
- assert (2*m).is_even == True
- assert (2*m).is_odd == False
-
- assert (-n).is_even == False
- assert (-n).is_odd == True
-
- assert (k*n).is_even == False
- assert (k*n).is_odd == True
-
- assert (k*m).is_even == True
- assert (k*m).is_odd == False
-
- assert (k*n*m).is_even == True
- assert (k*n*m).is_odd == False
-
- assert (k*m*x).is_even == True
- assert (k*m*x).is_odd == False
-
-def test_Add_is_even_odd():
- x = Symbol('x', integer=True)
-
- k = Symbol('k', odd=True)
- n = Symbol('n', even=True)
-
- assert (2+k).is_even == False
- assert (2+k).is_odd == True
-
- assert (7-k).is_even == True
- assert (7-k).is_odd == False
-
- assert (11-n).is_even == False
- assert (11-n).is_odd == True
-
- assert (-8+n).is_even == True
- assert (-8+n).is_odd == False
-
- assert (n+k).is_even == False
- assert (n+k).is_odd == True
-
- assert (n-k).is_even == False
- assert (n-k).is_odd == True
-
- assert (n+2*k).is_even == True
- assert (n+2*k).is_odd == False
-
- assert (k+n+x).is_odd == None
- assert (k+n-x).is_even == None
-
- assert (2*k+n*x).is_odd == None
- assert (2*k+n*x).is_even == None
-
def test_Mul_is_negative_positive():
x = Symbol('x', real=True)
y = Symbol('y', real=False)
@@ -591,37 +512,6 @@ def test_Mul_is_nonpositive_nonnegative():
assert (x*k).is_nonnegative == None
assert (u*v*n*x*k).is_nonnegative == None
-def test_Add_is_even_odd():
- x = Symbol('x', integer=True)
-
- k = Symbol('k', odd=True)
- n = Symbol('n', odd=True)
- m = Symbol('m', even=True)
-
- assert (k+7).is_even == True
- assert (k+7).is_odd == False
-
- assert (-k+7).is_even == True
- assert (-k+7).is_odd == False
-
- assert (k-12).is_even == False
- assert (k-12).is_odd == True
-
- assert (-k-12).is_even == False
- assert (-k-12).is_odd == True
-
- assert (k+n).is_even == True
- assert (k+n).is_odd == False
-
- assert (k+m).is_even == False
- assert (k+m).is_odd == True
-
- assert (k+n+m).is_even == True
- assert (k+n+m).is_odd == False
-
- assert (k+n+x+m).is_even == None
- assert (k+n+x+m).is_odd == None
-
def test_Add_is_negative_positive():
x = Symbol('x', real=True)
diff --git a/sympy/core/tests/test_eval_power.py
b/sympy/core/tests/test_eval_power.py
index 3f0ac6a..87d908f 100644
--- a/sympy/core/tests/test_eval_power.py
+++ b/sympy/core/tests/test_eval_power.py
@@ -38,12 +38,6 @@ def test_issue350():
assert ((a**Rational(1,3))**Rational(2)) == a**Rational(2,3)
assert ((a**Rational(3))**Rational(2,5)) == (a**Rational(3))**Rational(2,5)
- a = Symbol('a', real=True)
- b = Symbol('b', real=True)
- assert (a**2)**b == abs(a)**(2*b)
- assert sqrt(1/a) != 1/sqrt(a)
- assert (a**3)**Rational(1,3) != a
-
z = Symbol('z')
k = Symbol('k',integer=True)
m = Symbol('m',integer=True)
@@ -78,9 +72,7 @@ def test_issue1263():
def test_issue1496():
x = Symbol('x')
y = Symbol('y')
- n = Symbol('n', even=True)
assert (3-y)**2 == (y-3)**2
- assert (3-y)**n == (y-3)**n
assert (-3+y-x)**2 == (3-y+x)**2
assert (y-3)**3 == -(3-y)**3
diff --git a/sympy/core/tests/test_numbers.py b/sympy/core/tests/test_numbers.py
index 3e9cdfc..940886d 100644
--- a/sympy/core/tests/test_numbers.py
+++ b/sympy/core/tests/test_numbers.py
@@ -339,8 +339,7 @@ def test_issue324():
assert sqrt(x-1) != I*(1-x)**Rational(1,2)
def test_issue350():
- x = Symbol("x", real=True)
- assert sqrt(x**2) == abs(x)
+ x = Symbol("x")
assert sqrt(x-1).subs(x,5) == 2
diff --git a/sympy/functions/elementary/exponential.py
b/sympy/functions/elementary/exponential.py
index acb565d..24f1d49 100644
--- a/sympy/functions/elementary/exponential.py
+++ b/sympy/functions/elementary/exponential.py
@@ -45,16 +45,15 @@ def eval(cls, arg):
elif arg.is_Mul:
coeff = arg.as_coefficient(S.Pi*S.ImaginaryUnit)
- if coeff is not None:
- if (2*coeff).is_integer:
- if coeff.is_even:
- return S.One
- elif coeff.is_odd:
- return S.NegativeOne
- elif (coeff + S.Half).is_even:
- return -S.ImaginaryUnit
- elif (coeff + S.Half).is_odd:
- return S.ImaginaryUnit
+ if coeff and coeff.is_number:
+ if coeff % 2 == 0:
+ return S.One
+ elif coeff % 2 == 1:
+ return S.NegativeOne
+ elif (coeff + S.Half) % 2 == 0:
+ return -S.ImaginaryUnit
+ elif (coeff + S.Half) % 2 == 1:
+ return S.ImaginaryUnit
I = S.ImaginaryUnit
oo = S.Infinity
a = Wild("a", exclude=[I, oo])
diff --git a/sympy/functions/elementary/tests/test_exponential.py
b/sympy/functions/elementary/tests/test_exponential.py
index 37b9a54..5a331f7 100644
--- a/sympy/functions/elementary/tests/test_exponential.py
+++ b/sympy/functions/elementary/tests/test_exponential.py
@@ -21,11 +21,6 @@ def test_exp():
assert exp(3*pi*I/2) == -I
assert exp(2*pi*I) == 1
- assert exp(pi*I*2*k) == 1
- assert exp(pi*I*2*(k+Rational(1,2))) == -1
- assert exp(pi*I*2*(k+Rational(1,4))) == I
- assert exp(pi*I*2*(k+Rational(3,4))) == -I
-
assert exp(log(x)) == x
assert exp(2*log(x)) == x**2
assert exp(pi*log(x)) == x**pi
--
1.6.4
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