Hi Marc-Andre,
You did not read my previous mail carefully.
Use official ROOT versions and your problem will be solved.
In attachement, you will find the log of your checkfit program.
Rene Brun
On Sat, 22
Nov
2003,
Marc-Andre Pleier wrote:
> Hi Rene,
>
> thanks for the quick answer!
>
> I tried on a different machine with
> ROOT Version 3.05/04 28 April 2003,
> using gcc
> and
> ROOT Version 3.05/00 23 February 2003,
> using the KCC compiler - for me the problem
> still remains.
>
> I also tried on a completely different linux
> machine, independent of my experimental setup
> here, with ROOT Version 3.03/04 21 April 2002,
> and still see the problem.
>
> Please find attached a tar file with my sourcecode,
> Makefile and the text-output I get.
>
> Cheers,
> Marc-Andre.
>
>
> -----------------------------------------------------------------------------
> Marc-Andre Pleier Phone : +1 630 840 8575
> Fermilab D0 Fax : +1 630 840 8886
> P.O. Box 500, MS 352 Email: pleier@fnal.gov
> Batavia, IL 60510-0500, USA
> -----------------------------------------------------------------------------
>
> On Sat, 22 Nov 2003, Rene Brun wrote:
>
> > Hi Marc-Andre,
> >
> > I cannot reproduce this problem with the official versions 3.05/07 or
> > 3.10/01
> > see an example of log in attachement.
> >
> > Rene Brun
> >
> > On Sat, 22 Nov 2003, Marc-Andre
> > Pleier wrote:
> >
> > > Dear Rooters,
> > >
> > > I encounter the following problem (see attached sourcecode example
> > > for reproducing this...):
> > >
> > > Using a fitfunction I created myself which is used in a subroutine
> > > for a TF1 instantiation a la TF1 * myfit = new TF1("myfit",function,...);
> > > I am not able to extract the fit parameters that are printed on the
> > > screen by Minuit, if this subroutine is called more than once.
> > >
> > > For example fitting the same histogram more than once, I get the same
> > > Minuit output on the screen, but when I try to get the fit parameters
> > > from the second call on, the values returned are the parameter initial
> > > values instead of the Minuit values.
> > > This problem disappears when I call the TF1 destructor at the end
> > > of the subroutine.
> > >
> > > If I use the same subroutine with a predefined function like gaus,
> > > this problem doesn't show up.
> > > But if I don't put the TF1 destructor call in that routine as well,
> > > any call to my self-defined function after will again only
> > > return the parameter initial values instead of the Minuit values.
> > >
> > > Could somebody explain me why ROOT is behaving that way?
> > >
> > > To reproduce this effect, you can simply compile the attached code
> > > and switch the destructor calls on and off.
> > >
> > > I am using ROOT Version 3.05/00 23 February 2003.
> > >
> > > Cheers,
> > > Marc-Andre.
> > >
> > > -----------------------------------------------------------------------------
> > > Marc-Andre Pleier Phone : +1 630 840 8575
> > > Fermilab D0 Fax : +1 630 840 8886
> > > P.O. Box 500, MS 352 Email: pleier@fnal.gov
> > > Batavia, IL 60510-0500, USA
> > > -----------------------------------------------------------------------------
> > >
> > >
> > > Here is my code:
> > >
> > > #include <TF1.h>
> > > #include <TH1.h>
> > > #include <TFile.h>
> > > #include <iostream>
> > > using namespace std;
> > >
> > > double mygauss(Double_t *x, Double_t *par)
> > > {
> > > Double_t fitval = par[0]*exp(-.5*((x[0]-par[1])/par[2])*((x[0]-par[1])/par[2]));
> > > return fitval;
> > > }
> > >
> > > void fitmegood(TH1D * loose)
> > > {
> > > TF1 * myfit = new TF1("myfit", "gaus",50.,130.);
> > > myfit->SetParameters(7.,90.,4.);
> > > loose->Fit("myfit");
> > > cout << "fitpars : " << myfit->GetParameter(1) << " | " << myfit->GetParameter(2) << endl;
> > > // if we want fitmebad to work for all calls in the second block...
> > > //myfit->~TF1();
> > > return;
> > > }
> > >
> > > void fitmebad(TH1D * loose)
> > > {
> > > TF1 * myfit = new TF1("myfit", mygauss,50., 130., 3);
> > > myfit->SetParameters(7.,90.,4.);
> > > loose->Fit("myfit");
> > > cout << "fitpars : " << myfit->GetParameter(1) << " | " << myfit->GetParameter(2) << endl;
> > > // if we want fitmebad to work for second++ calls in the first block...
> > > //myfit->~TF1();
> > > return;
> > > }
> > >
> > > int main(void)
> > > {
> > > // Create a plot to be fitted...
> > > TF1 * willy = new TF1("willy", "gaus", 40., 140.);
> > > willy->SetParameters(7.42, 92., 3.5);
> > > TH1D* loose = new TH1D("willyplot", "test the fitting",100, 40., 140.);
> > > loose->FillRandom("willy", 150.);
> > >
> > > cout << "Fit using self-defined gaussian, block 1:" << endl;
> > > fitmebad(loose);
> > > fitmebad(loose);
> > > fitmebad(loose);
> > >
> > > cout << "Fit using predefined gaussian:" << endl;
> > > fitmegood(loose);
> > > fitmegood(loose);
> > > fitmegood(loose);
> > >
> > > cout << "Fit using self-defined gaussian, block 2:" << endl;
> > > fitmebad(loose);
> > > fitmebad(loose);
> > > fitmebad(loose);
> > >
> > > return 0;
> > > }
> > >
> > >
> > >
> >
>
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