How to solve this system using ODE45?
显示 更早的评论
The ODE system
dx/dt = -8/3 x + yz;
dy/dt = -10y + 10z;
dz/dt = -x*y + 28y - z when t=[0,50]
I only learned how to solve one equation each but,
I wanna solve this system using ODE45 on matlab
please help me how to make the script.
采纳的回答
Star Strider
2017-3-24
You first must assign ‘x’, ‘y’, and ‘z’ to a vector, then create the appropriate first-order differential equations with respect to each variable.
Example:
% % % MAPPING: x = v(1), y = v(2), z = v(3)
% dv(1,:) = -8/3.*v(1) + v(2).*v(3);
% dv(2,:) = -10*v(2) + 10*v(3);
% dv(3,:) = -v(1).*v(2) + 28*v(2) - v(3);
v_fcn = @(t,v) [-8/3.*v(1) + v(2).*v(3); -10*v(2) + 10*v(3); -v(1).*v(2) + 28*v(2) - v(3)];
ts = [0 50];
init_cond = [10; 10; 10];
[T,V] = ode45(v_fcn, ts, init_cond);
figure(1)
plot(T,V)
grid
I used an anonymous function here, simply for convenience. See the section on ‘Anonymous Functions’ in Function Basics for details on how to write them and use them.
更多回答（1 个）
Sameer kumar nayak
2020-1-25
0 个投票
7d²x/dt²+3dx/dt+5x+6=0 how can we solve using matlab using ode45??
1 个评论
Steven Lord
2020-1-25
See the "Nonstiff van der Pol Equation" example on this documentation page. You should be able to use the same techniques as that example to solve your ODE.
类别
在 帮助中心 和 File Exchange 中查找有关 Ordinary Differential Equations 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
