I need some manipulation with ODE45. Please help me!
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I just wondering that why this code working wrong. Please help me! I can't manipulate the ODE function.
options=odeset('RelTol',10^-4);
[T,Y]=ode23('turshilt23',[0 300],[0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5],options);
plot(T,Y);
function dy=turshilt23(t,y,flag)
%here is some code
if(k==0)
y(1)=y(1)/2;
end
dy(1)=mu*y(1)*(1-(y(1)/m_max));
%here is some code
end
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Answers (3)
Arnaud Miege
on 3 Aug 2011
Also, it seems that in your function turshilt23, you haven't defined what k, mu or m_max are. Finally you compute dy(1), but you call the ode solver with an initial condition vector of length 9. You need to compute dy(2), dy(3), ... dy(9) in your function as well.
Have a look at the documentation for the ode solvers, there are various examples you can inspire yourself from.
HTH,
Arnaud
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Tsogerdene
on 3 Aug 2011
2 Comments
Arnaud Miege
on 3 Aug 2011
It works for me. What error message do you get?
Some comments:
* Your function is a function of t, y and flag but t and flag are not used. Consider replacing those with ~
* Your function defines k and y_1 as global variables, but those aren't used in the function. You can remove those two lines.
The only changes I made were therefore:
function dy=turshilt23(~,y,~)
global Global_CycB1;
global Global_CycB2;
% global k;
% global y_1;
I used 0.1 for the other two global variables Global_CycB1 and Global_CycB2. The solver solved OK.
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