Solve system of differntial equation with one variable

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;

[Akhilkrishna Panamkoottathil Ramakrishnan]

How can i solve these 3 quations . Also i want to find how y1,y2,y3 varies from t=0 to t=1;

Answer 1

[Piotr Balik]

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)

[Akhilkrishna Panamkoottathil Ramakrishnan]

[Akhilkrishna Panamkoottathil Ramakrishnan]

When i tried the above code, i faced many errors. Could you please help me to solve this.

Thank you

[Star Strider]

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]

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