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Student Support Forum: 'fitting problem.. iteration??' topicStudent Support Forum > General > Archives > "fitting problem.. iteration??"

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tomato
06/23/03 04:05am

Hi,

Here I have a question which I cannot think of the right explanation..

I managed to come out with the equation which i used to plot the curve, providing that i fit the data points using NonlinearFit [data , ( A * Exp [ 1/ (wx) ] ) / ( B - x )^2 , { x , 1 / ( wx ) } , { {A ,3} , {B , 600} } ]. I specified a certain value for the A and B, whose values were what I got from MS Excel, I am able to get the correct equation as comparing to Excel equation. But I do not want to use MS EXcel due to certain constraints to fit such a complicated equation.

However, if I used this function: NonlinearFit [data , ( A * Exp [ 1/ (wx) ] ) / ( B - x )^2 , { x , 1 / ( wx ) } , { A , B } ] without specifying the value, I got another equation.

May I know if this is regarding the iteration which Mathematica use to fit or is it that there are many minima in the equation??

Is there any way of getting the correct equation while not specifying the value for A and B?

Thanks in advance.

regards,
tomato

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