Re: [ROOT] Fitting with stochastic optimizers

From: Eddy Offermann (eddy@rentec.com)
Date: Fri Mar 02 2001 - 16:22:18 MET


Hi Anton,

If we start to tinker/rewrite Minuit, I would like to see the following
additions/improvements:

1) This refers to linear fits:
    When fitting N data points and get M additional ones, I would like
    to ADD the information of the new ones to my Hessian matrix and
    gradient. I do NOT want to analyze all M+N data points again !
    This is important for on-line applications and non-cheating
    data analyss with time series. It is straightforward to implement
    for a least-squares objective function.
 
 2) Be able to easily specify Bayesian priors for my parameters
 
 3) Have possibilty of applying a robust algorithm instead
     of least squares like least median squares
     
What do others wish/think ??

Best regards Eddy

(out of town for the next 2weeks)
 
> X-Authentication-Warning: pcroot.cern.ch: majordomo set sender to 
owner-roottalk@root.cern.ch using -f
> From: "Anton Fokin" <anton.fokin@smartquant.com>
> To: "roottalk" <roottalk@pcroot.cern.ch>
> Subject: [ROOT] Fitting with stochastic optimizers 
> Date: Fri, 2 Mar 2001 11:42:49 +0100
> MIME-Version: 1.0
> Content-Transfer-Encoding: 7bit
> X-Priority: 3
> X-MSMail-Priority: Normal
> X-MIMEOLE: Produced By Microsoft MimeOLE V5.00.2615.200
> X-Filter-Version: 1.3 (ram)
> 
> Hi rooters,
> 
> I've just seen several postings about fitting. I am curious if someone ever
> went into troubles with root minuit and would like to have stochastic
> optimization as an alternative? I can provide simulated annealing/genetics
> if enough people want it.
> 
> Currently I have minimization functionality for TF1/2 user defined functions
> on www.smartquant.com/neural.html  I can extend the package so that it could
> be used with TVirtualFitter.
> 
> Regards,
> Anton
> 
> http://www.smartquant.com
> 
> 
> 

Eddy A.J.M. Offermann
Renaissance Technologies Corp.
Route 25A, East Setauket NY 11733
e-mail: eddy@rentec.com
http://www.rentec.com



This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:50:38 MET