Re: Accesssing fit parameters and errors

GetParErrors returns a pointer, so you just

do

Double_t* errors=fit.GetParErrors();

Then to get individual errrors you index it.

errora=errors[0];
errorb=errors[1];

etc.

GetParErrors only gives you the errors on each parameter. To get covariance matrix you have to dig deeper.

A.E. Snyder, Group EC                        \!c*p?/
SLAC Mail Stop #95                          ((.   .))
Box 4349                                        |
Stanford, Ca, USA, 94309                      '\|/`
e-mail:snyder_at_slac.stanford.edu                 o
phone:650-926-2701                              _
http://www.slac.stanford.edu/~snyder          BaBar
FAX:650-926-2657                          Collaboration

On Mon, 5 Feb 2007, Roger Mason wrote:

> Hello Arthur,
>
> "Arthur E. Snyder" <snyder_at_slac.stanford.edu> writes:
>
> > It would be nice if root Print commands could take ostream as an argument
> > so one could print to a file, but that doesn't work. I use cut&paste
> > sometimes, but it I want to print a lot of 'em to files I have to use
> > GetParError or GetParErrors (returns an array [a]).
> >
> >
> >
> > [a] a pointer to the array fParErrors.
> > virtual Double_t *GetParErrors() const {return fParErrors;}
> >
>
> I don't understand what syntax one would use to fill an array from
> GetParErrors, but I can easily loop over GetParError.
>
> Thanks,
> Roger
>
>
Received on Mon Feb 05 2007 - 22:24:03 CET