Re: large number of fit parameters

Tomasz Motylewski (motyl@stan.chemie.unibas.ch)
Wed, 02 Sep 1998 20:20:14 +0200 (MET DST)


On Wed, 2 Sep 1998, Rene Brun wrote:

> By default, Root creates a TMinuit object with 25 parameters.
> If you need more parameters, simply, do
> new TMinuit(55);

How it differs from:
gMinuit = new TMinuit(55);
?

I have another question: what to do, if I want to fix (not optimize at all)
some parameters in TGraph::Fit ? I have quite good starting values for them.
Before I run TGraph::Fit, I may not use gMinuit->mnfixp and then
gMinuit->mnfree (or may I?). After I run TGraph::Fit all my parameters are
changed.

I would suggest to add some "I" - init only option to ::Fit() - it would
perform everything without calling gMinuit->mnmigr() and printing statistics.
Then I have the gMinuit ready to run, but I can fine tune some parameters and
run it then.

Regards,

--
Tomasz Motylewski