[CC-ing to Chris Roat and debian-science since I originally suggested there that RooFit could be patched to use any of the fitter plugins.]
Unfortunately it looks like RooMinuit.cxx and RooFitResults.cxx can't currently be converted to use the TVirtualFitter interface. There are two main issues: 1) The function RooMinuit::contour() directly uses TMinuit::Contour(), a method which isn't accessible through TVirtualFitter (or even in TFitter). 2) The function RooFitResult::fillCorrMatrix() mucks about in the internals of the TMinuit class in order to obtain an error correlation matrix. There is no API for obtaining this matrix even in TMinuit, let alone in TVirtualFitter. I could submit a patch to fix RooFitResult::lastMinuitFit() and RooMinuit::synchronize() to use TVirtualFitter instead of gMinuit, but I guess there is not much point until (1) and (2) above are dealt with. Someday maybe these functionalities can be added to TVirtualFitter (and the classes that inherit from it) and RooFit can switch to use it completely. While looking into this, I also found a few other things in the core parts of ROOT that would be nice to fix eventually: - The TVirtualFitter class has a pure virtual interface GetParameter(int, char*, double&, double&, double&, double&) - it would be nice to also have a version of this function where the second argument is a TString&, in order not to worry about string lengths when calling it. - The TVirtualFitter class has static functions GetErrorDef() and SetErrorDef(). First, shouldn't these be class members so that each instance of TVirtualFitter can have a separate value? Second, the TFitter class based on Minuit seems to completely ignore those functions: TMinuit has its own SetErrorDef() function, but TFitter does nothing with it. To conclude, currently libRooFit is constrained to depend specifically upon libMinuit. I do apologize for wasting people's time because I thought otherwise at first. For the ROOT Debian packages, I think therefore libRooFit cannot be packaged as a library unless libMinuit is also packaged as a library. Or, they could both be packaged just as plugins. best regards, -- Kevin B. McCarty <[EMAIL PROTECTED]> Physics Department WWW: http://www.princeton.edu/~kmccarty/ Princeton University GPG: public key ID 4F83C751 Princeton, NJ 08544 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
