How to pass values from one ode to another ode?
2 次查看(过去 30 天)
显示 更早的评论
I av to use the results of one ode(ode45) inside another ode... here is my code:
1st ode function
function dw=sd(t,w)
va=10;
vb=0;vc=0;
%MOMENT OF INERTIA IN PRINCIPAL AXIS
I1=27;
I2=17;
I3=25;
%DIFFERENTIAL EQUATIONS
dw(1,1)= ((I2-I3)/I1)*w(2)*w(3)+(va/I1);
dw(2,1)=((I3-I1)/I2)*w(1)*w(3)+(vb/I2);
dw(3,1)=((I1-I2)/I3)*w(1)*w(2)+(vc/I3);
function cal
[t,W]=ode45('sd',[tinit tfinal],[0;0;0]);
i av use the results of these in another ode function below
function dq=sk(t,q,w1,w2,w3)
dq(1,1)=0.5*(w3*q(2)-w2*q(3)+w1*q(4));
dq(2,1)=0.5*(-w3*q(1)+w1*q(3)+w2*q(4));
dq(3,1)=0.5*(w2*q(1)-w1*q(2)+w3*q(4));
dq(4,1)=0.5*(-w1*q(1)-w2*q(2)+w3*q(3));
end
function cal
[t,Q]=ode45('sk',[tinit tfinal],[0;1;0;0],W(:,1),W(:,2),W(:,3))
there s some error in passing as shown aabove
any suggestion pl?
0 个评论
回答(2 个)
ChristianW
2013-2-10
Write all equations in 1 function and make your state vector like this: 'x = [w;q]'. Tell me, if you need more details.
the cyclist
2013-2-10
When you call ode45() the second time, with the function 'sk', you are calling it with 4 input arguments, but I don't think you've got the input structure correct.
If you run your code after first having done
>> dbstop if error
you will see that your W(:,1) vector is being interpreted by ode45() as the options input.
另请参阅
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!