# Why ode45 is not working??

3 ビュー (過去 30 日間)
Frane 2021 年 7 月 19 日

Hello,
I've uploaded the two following files:
1. epas_steering_system.m is the main file, and it is the file where ode45 gives me an error,
2. epasFun.m is the function file.
My question is, does somebody know why ode45 won't work?
Thanks.
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Frane 2021 年 7 月 22 日
I checked the parameters, they are okey; checked the equations, they are okey.
It could be something with the code itself (probably with the ode45 part). To be honest I don't know what, and I'm stuck at the moment.

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### 回答 (1 件)

Tesfaye Girma 2021 年 7 月 21 日
you can try this approach if it worked for you
f = (t,y) [ 4.86*y(3) - 4.86*10^14*y(1)*y(2);
4.86*y(3) - 4.86*10^14*y(1)*y(2);
-4.86*y(3) + 4.86*10^14*y(1)*y(2) ];
opt = odeset('maxstep',1e-13);
tspan = [0 1e-11];
y0 = [1.48e-8; 6.7608e-3; 1];
[t,y] = ode45(f,tspan,y0,opt);
subplot(311)
plot(t,y(:,1))
subplot(312)
plot(t,y(:,2))
subplot(313)
plot(t,y(:,3))
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Frane 2021 年 7 月 22 日

Where did you get this numbers that are multiplying y(1), y(2) and y(3) in f=(t,y), and the numbers from y0?
Did you try my code and added these numbers and it worked or?
And what should y(1), y(2) and y(3) represent?

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