I have set PrintLevel(-1) and Verbose(kFALSE) when doing a fit via RooFit. It indeed suppressed lots of output. However, there are several types of output still existing.
RooFitResult::fillCorrMatrix: number of floating parameters <=1, correlation matrix not filled
MINUIT WARNING IN PARAMETR
============== VARIABLE1 BROUGHT BACK INSIDE LIMITS.
So what should I do in order to suppress these two kinds of output? Thanks a lot.
I will fix the warning about the correlation parameters in the next version of RooFit,
it is not conditional on anything at the moment so you cannot suppress it right now,
this is a bug.
Concerning the MINUIT message, this is the same issue, but not under my control
because this message is generated inside TMINUIT and is not governed by
the printLevel of minuit. Perhaps Lorenzo can comment on this?