Solving coupled ODEs via ode45
显示 更早的评论
Hello,
I have 2 secound order and coupled ordinary differential equations. For the first equation, I could find an explicit solution, i.e. d^2y/dt^2=.....
However, for the second equation, I could not find an explicit solution. Therefore, I couldn't use ode45 etc. How can I solve these equations numerically?
Thank you in advance
4 个评论
Torsten
2024-3-2
If you don't know the equation, how do you want to solve it ? Or what do you mean by
However, for the second equation, I could not find an explicit solution. Therefore, I couldn't use ode45 etc.
Seymen
2024-3-2
Torsten
2024-3-2
ode45 can solve first-order initial value problems. Thus your equations must be of the form dy/dt = f(t,y).
If you have a second-order differential equation
d^2y/dt^2 = g(t,y,dy/dt)
, it can be written as two first-order differential equations by putting
z(1) = y, z(2) = dy/dt
The system then reads
dz(1)/dt = z(2)
dz(2)/dt = g(t,z(1),z(2))
Steven Lord
2024-3-2
Can you show us the form of the differential equations that you do know? If you show us the mathematical equations we may be able to help you translate them into MATLAB code.
回答（1 个）
Sulaymon Eshkabilov
2024-3-3
0 个投票
If your equation is implicit then, ode15i might be the tool to use.
类别
在 帮助中心 和 File Exchange 中查找有关 Ordinary Differential Equations 的更多信息
2024-3-3
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
