Python求解含有未知数的矩阵的特征值和特征向量

Question

代码

import math
from sympy import *
f=sympy.Function('f')

a=1
t = symbols('t',real=true)
f=np.array([[2 - math.e**(-a * t), math.e**(-a * t / 2)], [math.e**(-a * t / 2), math.e**(-a * t)]])
w, v = np.linalg.eig(f)
print('特征值：{}\n特征向量：{}'.format(w, v))

然后系统报错
File "E:\ProgramData\Anaconda3\lib\site-packages\numpy\linalg\linalg.py", line 1317, in eig
_assert_finite(a)
File "E:\ProgramData\Anaconda3\lib\site-packages\numpy\linalg\linalg.py", line 207, in _assert_finite
if not isfinite(a).all():
TypeError: ufunc 'isfinite' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''（TypeError: ufunc 'isfinite'不支持输入类型，并且根据类型转换规则" safe "不能安全地强制输入到任何受支持的类型。）