ODE with discrete, external input
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Hi everybody, I want to solve a simple ODE for specific discrete time points in which constats are updated externally for each specific t value. vgr
t=1:100; dy/dt=kt;
where k is a external vector with length=length(t) and wich is considered in the equation for each t.... any help? thanks in advance
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Accepted Answer
Arnaud Miege
on 5 Apr 2011
2 Comments
Sergio
on 31 Oct 2014
Hi Arnaud Miege, what would you suggest if the discrete ODE is a (2x2) system? Expanding the first question
t=0:0.02:1;
dxdt = Constant*K1;
dydt = Constant*K2;
where K1 and K2 are both external vector with length=length(t)? and both depending of two variables (x,y)?
Interp1 from matlab would be wrong since we would be interpolating in one dimension while the system is 2D.
More Answers (1)
Torsten
on 31 Oct 2014
Use
if K1 and K2 don't depend explicitly on t, but on the dependent variables x and y.
Best wishes
Torsten.
4 Comments
Sergio
on 31 Oct 2014
Edited: Sergio
on 31 Oct 2014
Thanks! but I still don't understand! Sorry!
I have another example here which is more easier but which can help me to understand.
Assume I have:
x1 = 40:0.005:55;
x1=x1';
x2=40:0.005:55;
x2=x2';
And then I discretize the following function:
V1=x1.*(0.2-0.005*x2);
V2=x2.*(-0.5+0.01*x1);
How can I use griddata now? And how can I solve this as an ODE?
Torsten
on 3 Nov 2014
Sorry, but meanwhile, I don't understand what you are trying to do.
Please specify more clearly:
What is the ODE you are trying to solve ?
Which MATLAB program are you trying to use to solve your ODE ?
Which kind of external input data do you have and where do they enter the ODE ?
Best wishes
Torsten.
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