SymPy - 求解方程中的变量

Question

是否有可能定义一个方程并求解该方程中的变量？

D_PWM, Rsense, A = symbols('D_PWM, Rsense, A')

i_out = D_PWM * (A/Rsense)

print i_out

solve(i_out, Rsense)

结果:

A*D_PWM/Rsense
[]

Answer 1

i_out尚未被声明为符号.

>>> from sympy import *
>>> var('D_PWM, Rsense, A i_out')
(D_PWM, Rsense, A, i_out)
>>> eqn=Eq(i_out,D_PWM * (A/Rsense))
>>> solve(eqn,Rsense)
[A*D_PWM/i_out]