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Subject: Re: (yet unsolved) how to Solve coupled ODEs
Date: Tue, 12 Feb 2013 16:07:18 +0000 (UTC)
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"Henry" wrote in message <kfb8m3$mom$1@newscl01ah.mathworks.com>...
> Problem not yet solves, any helps please?

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. 

If you start with s=0 as I suggested in the call to ode45, you will get problems in the evaluation of dyds(2,1) because of the term y(2)/s (division by zero).
Please supply the values of the parameters a,b,c,d and e, the interval of integration and the error message you received.

Best wishes
Torsten.