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Gaetano Barbato
01/31/05 05:22am


I'm using mathematica 5.0, and trying to perform the following minimization:
I have a set of data (x,y) to fit with a non linear equation:

x = (y/a) + b/a ( ln(y0 /(y0-y) ) )

Where y0 = 0.000250, and a,b are the parameters to optimize.

First guess values for a= 0.000003 , b= 0.000034

The minimization should be obtained by minimizing the SUM(xexp - xcalc)^2

the exp data are of the type:
y x
0.006 0.050
0.011 0.100
0.016 0.200
0.019 0.300
0.024 0.500
0.034 1.000
0.042 1.500
0.051 2.000

The way I implemented this is following the guidelines of one of your posted questions, these are the exact steps I did and the Mathematica response: first I write the guessed parameters (a,b) and generate with the equation a table of data, to see if the equation is well understood by the software. Then I try to fit the data generated with the equation by varying the data (a,b). Here I got errors.

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Subject (listing for 'non linear fit')
Author Date Posted
non linear fit Gaetano Barb... 01/31/05 05:22am
Re: non linear fit Forum Modera... 01/31/05 10:19am
Re: non linear fit Gaetano Barb... 02/01/05 02:59am
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