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Topic: how to Solve coupled ODEs
Replies: 5   Last Post: Feb 12, 2013 11:07 AM

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Torsten

Posts: 1,471
Registered: 11/8/10
Re: how to Solve coupled ODEs
Posted: Feb 8, 2013 2:47 AM
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"Henry" wrote in message <kf0n7c$k5i$1@newscl01ah.mathworks.com>...
> Hi Torsten,
> Would you kindly indicate which are the mistakes in my code?
> thanks! Henry


Just compare line for line:

global a b c d e
a=...;
b=...;
c=...;
d=...;
e=...;
[t,y] = ode45(@odeeqns, [0 3], [1 1]);

function dyds = odeeqns(s,y)
global a b c d e
dyds = zeros(2,1)
dyds(1,1) = 1/y(1) *(y(2)*(d+s /y(2))-a *y(1)*sqrt(y(1)^2+(e+y(2))^2));
dyds(2,1) = -(y(2)*(b+y(2))*sqrt(y(1)^2+(e+y(2))^2))/y(1)-y(2)/s - c;

Best wishes
Torsten.



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