solve() "Unable to find explicit solution"
显示 更早的评论
Using solve for an equation is not working and I'm not sure why. This has an explicit solution but it doesn't work. What am I missing?
syms g m L s Y(s)
solve(- m*(s - s^2*Y(s) + 1)*L^2 + g*m*Y(s)*L == 0,Y(s))
采纳的回答
Dyuman Joshi
2023-10-13
solve() expects the 2nd input to be an array of symbolic variable(s), where as you have defined Y as a symbolic function.
If you want to get the output as a function of "s", define it accordingly -
syms g m L s Z
Y(s) = solve(- m*(s - s^2*Z + 1)*L^2 + g*m*Z*L == 0,Z)
更多回答（2 个）
Hi @Andrew
If this is related to deriving the transfer function using Laplace transform, then I prefer using the isolate() function.
syms g m L s Y(s)
Eqn = - m*(s - s^2*Y(s) + 1)*L^2 + g*m*Y(s)*L == 0;
Eqn = isolate(Eqn, Y(s))
(I am absolutely positive I had already answered this, but there is no trace of that...)
solve() cannot solve for functions. You will need to substitute a symbolic variable for the function. For example,
syms g m L s Y(s) Ys
eqn = - m*(s - s^2*Y(s) + 1)*L^2 + g*m*Y(s)*L == 0;
solve( subs(eqn, Y(s), Ys), Ys)
类别
在 帮助中心 和 File Exchange 中查找有关 Symbolic Math Toolbox 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
