Question

我试图增加对变量的时间依赖性。我已经使用sympy定义了变量（theta和theta_dot）。在计算偏导数时没有问题，但是在计算相对于时间的总导数时遇到麻烦。

我正在处理的方程式是Euler Lagrange方程式。

enter image description here

我用过sympy

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和

diff(L,theta)

查找偏导数。

理想情况下，我想知道一种将时间导数整合到方程中的好方法。

Answer 1

您可以在sympy中使用dynamicsymbols。

list_of_variables=[dynamicsymbols("theta"),dynamicsymbols("theta",1)]

f = diff(diff(i, list_of_variables[1]), 't') - diff(i, list_of_variables[0])

这是类似的帖子。

https://math.stackexchange.com/questions/3014868/euler-lagrange-formalism-with-sympy

增加对变量的时间依赖性

1 个答案: