32 lines
1.1 KiB
Python
32 lines
1.1 KiB
Python
from sympy.core.numbers import I
|
|
from sympy.core.symbol import symbols
|
|
from sympy.functions.elementary.exponential import exp
|
|
from sympy.functions.elementary.trigonometric import (cos, cot, sin)
|
|
from sympy.testing.pytest import _both_exp_pow
|
|
|
|
x, y, z, n = symbols('x,y,z,n')
|
|
|
|
|
|
@_both_exp_pow
|
|
def test_has():
|
|
assert cot(x).has(x)
|
|
assert cot(x).has(cot)
|
|
assert not cot(x).has(sin)
|
|
assert sin(x).has(x)
|
|
assert sin(x).has(sin)
|
|
assert not sin(x).has(cot)
|
|
assert exp(x).has(exp)
|
|
|
|
|
|
@_both_exp_pow
|
|
def test_sin_exp_rewrite():
|
|
assert sin(x).rewrite(sin, exp) == -I/2*(exp(I*x) - exp(-I*x))
|
|
assert sin(x).rewrite(sin, exp).rewrite(exp, sin) == sin(x)
|
|
assert cos(x).rewrite(cos, exp).rewrite(exp, cos) == cos(x)
|
|
assert (sin(5*y) - sin(
|
|
2*x)).rewrite(sin, exp).rewrite(exp, sin) == sin(5*y) - sin(2*x)
|
|
assert sin(x + y).rewrite(sin, exp).rewrite(exp, sin) == sin(x + y)
|
|
assert cos(x + y).rewrite(cos, exp).rewrite(exp, cos) == cos(x + y)
|
|
# This next test currently passes... not clear whether it should or not?
|
|
assert cos(x).rewrite(cos, exp).rewrite(exp, sin) == cos(x)
|