python - 如何简化sympy中的指数对数？

Question

当我打字时

import sympy as sp
x = sp.Symbol('x')
sp.simplify(sp.log(sp.exp(x)))

我得到

log(e^x)

代替 x。我知道此功能“没有任何保证”。

Question. Is there some specific simplification (through series expansion or whatsoever) to convert logarithm of exponent into identity function?

Answer 1

您必须将 x 设置为实型，您的代码才能正常工作:

import sympy as sp
x = sp.Symbol('x', real=True)
print(sp.simplify(sp.log(sp.exp(x))))

输出:x。

对于复杂的x，此公式的结果并不总是等于x。例子是 here .