Hi,
Thanks for the suggestion, but it didn’t make a difference.
I think the problem is the covariance matrix due to the same reason as descrived in Note2 of this reference: http://root.cern.ch/root/html/TF1.html#TF1:IntegralError
Since there is a constant parameter in my pdf, the RooFit doesn’t include it in the matrix.
My code is too involved to put here, but please have a look at his older post:
[url]IntegralError and RooBernstein
There is a .C file attached (and it runs). This is very similar to what I do (I fit to a Bernstein with constant p0 parameter). Except that in the example the fit is performed to S+B, while I just fit the distribution to B only.
So, if you could help resove the issue in that posting it would probably resolve my problem as well.
Thanks,
Andrey