Re: TMinuit Class

Hi Daniel,
To get the result of a parameter you do: gMinuit->GetParameter(index,parameter,parameter_uncertainty); That is when you use Migrad. If Minos errors: gMinuit->mnerrs(index, Err1, Err2,...);

I think you can use:
gMinuit->mnemat(&cov[][],nparFree);
to get the covarience matrix.
Arafat

On Tue, 22 Mar 2011, 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 Tue Mar 22 2011 - 19:50:14 CET