在 Sympy 中,我尝试求解这样的微分方程:
from sympy import *
from sympy.physics.vector import dynamicsymbols
x = dynamicsymbols('x')
diffeq = Eq(x(t).diff(t), x(t))
dsolve(diffeq, x(t))
但这又回来了
TypeError Traceback (most recent call last)
<ipython-input-10-8a45d7148b24> in <module>()
1 x = dynamicsymbols('x')
----> 2 diffeq = Eq(x(t).diff(t), x(t))
3 dsolve(diffeq, x(t))
TypeError: 'x' object is not callable
据我了解,
dynamicsymbols
创建了一个t的函数,那么如何在微分方程中使用它?
Sympy 文档有点混乱...当你打印变量时
x
print(x)
你得到了字符串
x(t)
但是,这并不意味着应该在方程中调用
x(t)
,而只是使用变量 x
:
from sympy import *
from sympy.physics.vector import dynamicsymbols
x = dynamicsymbols('x')
diffeq = Eq(diff(x, Symbol('t')), x)
dsolve(diffeq, x) # Eq(x(t), C1*exp(t))