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 Author Comment/Response Frank Solina Gilbert 10/01/05 08:26am Hi yehuda :), Thanks for replying to my request. Your are right I really should use A,B,C,DD as variables, but the code really works for the first case. Because I have the data set, and yes normally you have to define A,B,C,DD before you apply NDSolve . But I have the my idea from the very same wolfram forum. Here is the URL: http://support.wolfram.com/mathematica/mathematics/stats/ndsolvefit.html. Believe me, it really works, because this type of code enables Mathematica to start with own initial guesses. You even don't need to give the variables A,B,C,DD before. The problem I have is the second kind of the code. Because I have only one differential equation and 2 unknowns u[t] and g[t]. That would mean that I have to define g[t] brfore. But how??? g[t] is the input to the system whereas the u[t] describes the system's response. g[t] is a randomly generated function, defined only by the experimental conditions I have. Is there a way that I at least can define or describe a little bit g[t], before using it as an input. Best regards, FranK URL: ,

 Subject (listing for 'Data Fitting to Differential Equations') Author Date Posted Data Fitting to Differential Equations Dr. Frank So... 09/28/05 6:01pm Re: Data Fitting to Differential Equations yehuda ben-s... 09/30/05 00:25am Re: Data Fitting to Differential Equations Frank Solina... 09/30/05 4:12pm Re: Data Fitting to Differential Equations Frank Solina... 10/01/05 08:26am Re: Data Fitting to Differential Equations yehuda ben-s... 10/02/05 2:20pm Re: Data Fitting to Differential Equations FRanc Solina... 10/05/05 4:48pm Re: Data Fitting to Differential Equations Franc Solina... 10/13/05 09:12am
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