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Re: exponential fitting

 From: Gert Van den Eynde Subject: Re: exponential fitting Date: Wed, 4 Sep 2002 16:47:49 +0200

```On Wed, 4 Sep 2002 16:41:39 +0200

> Fine. It's working now, thanks a lot.
>
> expfit is nice, really. the only two problems are:
> 1.) the data is shifted very often, that's why I need the 'c'
> {y=a*exp(b*x)+c}.

expfit will return a term where b = 0 and a is the constant 'c' you're looking
for (exp(0*x) = 1).

> 2.) expfit doesn't calculate the R^2 for me.
> maybe I get rid of these, but if you have already a solution - just tell me.

expfit returns the root mean square (rms):
sqrt(sum((data(i)-fitting_evaluation(i))**2)), you would want to square this,
no ?

Hope this helps,

Gert Van den Eynde

SCK-CEN
Reactor Physics & MYRRHA Dept
Mol,Belgium

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