need help with non linear regression

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mayyan

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input: X= [X1 , X2 ,...,Xn] ; Y= [Y1 , Y2 ,...,Yn]

I want to find a solution of the type:
y = C1*exp{(a+ib)t}+C2*exp{(a-ib)t} or y = D1*exp{-at}*Sin(bt+p)

( which is the solution of: y'' + A0*y' + A1*y = 0 with complex roots ). I want to do it using regression to best fit the input.

Does someone know a book ( preferably Ebook) or internet site with an algorithm? Or have other idea how to solve it using different method?

please let me know
thanks
Mayyan
 

try Matlab with Curve Fit Tools

type on workspace: cftool

you can find linear polynomial , quadratic polynomial , cubic polynomial and 4th degree to 9th degree polynomial fits.

I always use this toolbox. It´s very powerfull e easy.

ATLAJ
 

Thanks for replying but the phisical nature of my problem make it look like:

y = D1*exp{-at}*Sin(bt+p)

and since my sampling points are few and far from each other the polinomial way want give me satisfactory solution.
 

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