Re: TMinuit Class

Hi Daniel,

 For retrieving the parameters and errors you can use

TMinuit::GetParameter

http://root.cern.ch/root/htmldoc/TMinuit.html#TMinuit:GetParameter

and for the error matrix

TMinuit::mnemat

http://root.cern.ch/root/htmldoc/TMinuit.html#TMinuit:mnemat

Best Regards

 Lorenzo

On Mar 22, 2011, at 7:35 PM, Daniel A. Fagundes wrote:

> Hi,
> i made a fit using the TMinuit objects. Here goes part of the macro:
>
> TMinuit *gMinuit = new TMinuit(4);
> gMinuit->SetFCN(fcn);
>
> Double_t arglist[10];
> Int_t ierflg = 0;
>
> arglist[0] = 1;
> gMinuit->mnexcm("SET ERR", arglist ,1,ierflg);
>
> Double_t vstart[4] = {9.05424e+03,-3.58569e+03,3.72278e+02,1.0};
> Double_t step[4] = {1.0, 1.0, 1.0,1.0e-01}; //passos
> gMinuit->mnparm(0, "a0", vstart[0], step[0], 0,0,ierflg);
> gMinuit->mnparm(1, "a1", vstart[1], step[1], 0,0,ierflg);
> gMinuit->mnparm(2, "a2", vstart[2], step[2], 0,0,ierflg);
> gMinuit->mnparm(3, "a3", vstart[3], step[3], 0,0,ierflg);
>
> arglist[0] = 1000;
> arglist[1] = 1.0;
> gMinuit->mnexcm("MIGRAD", arglist ,5,ierflg);
>
> Double_t amin,edm,errdef;
> Int_t nvpar,nparx,icstat;
> gMinuit->mnstat(amin,edm,errdef,nvpar,nparx,icstat);
> gMinuit->mnprin(3,amin);
>
> The problem is: I don't know how to get the parameters and the error matrix (unless I copy them from the output of terminal).
> Can anyone help me?
> I appreciate it very much.
> Cheers,
> Daniel.
>
>
> -----------------------------------------------------------------------------------------
> Daniel Almeida Fagundes
> Estudante de Doutorado - PhD Physics Student
> Universidade Estadual de Campinas - UNICAMP
> Instituto de Física Gleb Wataghin - IFGW
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Received on Wed Mar 23 2011 - 09:01:52 CET