Solve system of differntial equation with one variable

1 次查看（过去 30 天）
Akhilkrishna Panamkoottathil Ramakrishnan
评论： Akhilkrishna Panamkoottathil Ramakrishnan 2021-1-4
dydt= f(t,y)
t=0:0.0.1:1;
dydt(1) = ( 1.15125859*10^-17)*1i;
dydt(2) = ( 2.77307307*10^-17)*1i;
dydt(3) = ( 8.3780271*10^-17)*1i;

请先登录，再回答此问题。

回答（1 个）

Piotr Balik
Piotr Balik 2021-1-3
One easy way to solve ODE's is using ode45 solver.
Define your derivative function in separate file, just as in your question:
function dydt = myODE(t,y)
dydt(1) = (1.15125859*10^-17)*1i;
dydt(2) = (2.77307307*10^-17)*1i;
dydt(3) = (8.3780271*10^-17)*1i;
end
And call for the solver:
t=0:0.01:1;
initial=[0 0 0]'; %column form
[t,y]=ode45(@myODE,t,initial);
%visualize
plot(t,y)
  4 个评论
显示 2更早的评论
Star Strider
Star Strider 2021-1-4
Change the function to:
function dydt = myODE(t,y)
dydt = zeros(3,1);
dydt(1) = (1.15125859*10^-17)*1i;
dydt(2) = (2.77307307*10^-17)*1i;
dydt(3) = (8.3780271*10^-17)*1i;
end
That will produce a column vector (the default is a row vector), and the code should work.
Akhilkrishna Panamkoottathil Ramakrishnan
Akhilkrishna Panamkoottathil Ramakrishnan 2021-1-4
The code worked.
But i got a warning, "complex parts of imaginary numbers x and y are ignored ".
Also all the results are.
Actually from the above 3 equations, i want to find y1,y2,y3. where t varies from 0 to1.
Can anyone help?
Thank you

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Programming 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by