Why ode45 is not working??

14 vues (au cours des 30 derniers jours)
Frane
Frane le 19 Juil 2021
Modifié(e) : Frane le 22 Juil 2021
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.
  35 commentaires
Torsten
Torsten le 21 Juil 2021
According to the equations you posted, they seem to be implemented correctly in epasFun.
Of course, I can't tell whether they are correct or whether the parameters you chose make sense.
Frane
Frane le 22 Juil 2021
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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Tesfaye Girma
Tesfaye Girma le 21 Juil 2021
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))
  3 commentaires
Tesfaye Girma
Tesfaye Girma le 22 Juil 2021
you are right thank you brother!!
Frane
Frane le 22 Juil 2021
Modifié(e) : Frane le 22 Juil 2021
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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