Re: how to re-calculate error matrix in TMinuit

From: Arthur E. Snyder <snyder_at_slac.stanford.edu>
Date: Mon, 14 May 2007 08:23:27 -0700 (PDT)


What kind of weight are you referring too? There are no explicit weights in a maximum likelihood fit.

-Art S.

PS. Generally, speaking minuit is not going to recompute errors for you without rerunning the fit.

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On Sat, 12 May 2007, X. Lu, Peking Univ. wrote:

> Dear Rooter,
>
> I have the following question about TMinuit:
>
> I have performed a Maximum Likelihood fit using TMinuit, and obtained
> estimated parameters and errors.
> Then I want to get a new error matrix by changing some variables (such as
> weight) at the found minimum of the -log likelihood function.
> How can I do this without performing a new minimization procedure of TMinuit
> ?
>
> Thanks in advance !
>
> Best Regards,
> Xianguo
>
> --
> Take flight into the sky, beyond the moon, beyond my mind.
>
> Xianguo LU
> Physics Department, Peking University
> Beijing, China
> Tel: 0086-10-62753888(o)
>
Received on Mon May 14 2007 - 17:23:39 CEST

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