Fumili doesnt work through TVirtualFitter

Hello rooters,
I try to use the Fumuli algorithm through TVirtualFitter interface, as described in the UserGuide, but the error is appeared:
FumiliMinimizer: Error : wrong FCN type. Try to use default minimizer
Switching to Minuit deliver from this error and program works properly. How to remove this error?

Thanks in advance

I do not see any problem with Fumili and TVirtualFitter.
See an example in tutorial minuit2FitBench.C

When posting to this Forum, please always indicate which version you use
and provide the shortest possible running script reproducing your problem.


Sorry, version is 5.08/00.
If add the string TVirtualFitter::SetDefaultFitter(“Fumili2”) to the test/minexam.cxx it is appeared the same error.

Use TVirtualFitter::SetDefaultFitter(“Fumili”)

Unfortunatly, I see that the “CALL FCN” was not implemented
in Minuit2 and Fumili2. The fix will be today in CVS.


I have fixed in CVS for Minuit2. The minexam.cxx example now will work if you set Minuit2.

However, the example cannot work with both Fumili and Fumili2.
Fumili works with Chi2 or Likelihood FCN, and it requires you implement the derivatives for each term. To make it work you would need to modify the fcnk0() function in minexam to calculate as well the derivatives.