Python 复数的数学运算

>>> a = complex(2, 4)
>>> b = 3 - 5j
>>> a
(2+4j)
>>> b
(3-5j)
>>>

>>> a.real
2.0
>>> a.imag
4.0
>>> a.conjugate()
(2-4j)
>>>

>>> a + b
(5-1j)
>>> a * b
(26+2j)
>>> a / b
(-0.4117647058823529+0.6470588235294118j)
>>> abs(a)
4.47213595499958
>>>

>>> import cmath
>>> cmath.sin(a)
(24.83130584894638-11.356612711218174j)
>>> cmath.cos(a)
(-11.36423470640106-24.814651485634187j)
>>> cmath.exp(a)
(-4.829809383269385-5.5920560936409816j)
>>>

>>> import numpy as np
>>> a = np.array([2+3j, 4+5j, 6-7j, 8+9j])
>>> a
array([ 2.+3.j, 4.+5.j, 6.-7.j, 8.+9.j])
>>> a + 2
array([ 4.+3.j, 6.+5.j, 8.-7.j, 10.+9.j])
>>> np.sin(a)
array([ 9.15449915 -4.16890696j, -56.16227422 -48.50245524j,
        -153.20827755-526.47684926j, 4008.42651446-589.49948373j])
>>>

>>> import math
>>> math.sqrt(-1)
Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
ValueError: math domain error
>>>

>>> import cmath
>>> cmath.sqrt(-1)
1j
>>>