Hi, there seems to be a limit of 50 parameters that can be fitted at a time. Is there any way to circumvent this? Is this a limit of MINUIT or the PDL implementation?
Thank you! Cheers, Rahman On Thu, 2007-06-21 at 14:48 +0200, Andres Jordan wrote: > I've included an interface to Minuit as a new module PDL::Minuit in the > PDL distribution, so if you get fresh source from the cvs you can get it. > > Alternatively for those who would like to try this without recompiling > PDL at this point, I have put a standalone tarball at: > > http://www.eso.org/~ajordan/PDL-Minuit-1.0.tgz > > Enjoy (assuming the compilation goes smoothly....). > > -Andres > > Rahman Amanullah wrote: > > Hi Andres, > > > > I want to do exactly what Karl explicitly wrote in his email, solve a > > non-linear Chi2 problem with an arbitrary weight matrix. Minuit is > > perfect for this, and if you think you will have a PDL interface ready > > within a few days, that would just be fabulous! > > > > Cheers, > > > > Rahman > > > > On Thu, 2007-06-14 at 22:33 +0200, Andres Jordan wrote: > > > >> I have indeed written a PDL interface to Minuit which I've been > >> intending to post here for a while (for a long time I was chasing a > >> small mem leak in the interface but finally solved that some months > >> ago). Minuit is very flexible and robust minimization package. I will > >> clean up the code a bit, finish the documentation and finally post this > >> in the next few days. > >> > >> Rahman: I am bit confused as to what you mean by inputting the > >> covariance matrix. There is a Minuit manual at: > >> http://wwwasdoc.web.cern.ch/wwwasdoc/minuit/minmain.html which might > >> help you in determining if Minuit will help you with what you want. > >> > >> -Andres > >> > >> > >> Karl Glazebrook wrote: > >> > >>> I would have thought that one could easily modify any of these fairly > >>> easier by just changing > >>> the way it computes the goodness of fit metric. > >>> > >>> i.e. something like chi^2 = D^T I D where I is the inverse of the > >>> covariance matrix and D = Data - Model matrix > >>> > >>> Andreas Jordan has written a PDL interface to MINUIT. Andreas please > >>> speak up! > >>> > >>> Karl > >>> > >>> On 14/06/2007, at 2:14 PM, Rahman Amanullah wrote: > >>> > >>> > >>>> Hi, > >>>> > >>>> I'm looking for a fitter in PDL that takes an *input* covariance matrix. > >>>> My data is heavily correlated and I need to take this into account in my > >>>> fit. > >>>> > >>>> So far I've been looking at PDL::Fit::LM and PDL::Fit::Levmar but none > >>>> of these appear to have this feature. It's possible to pass weights to > >>>> PDL::Fit::LM, but not a full covariance matrix so the input data is > >>>> still treated as uncorrelated in the fit. > >>>> > >>>> If there is no existing fitter that supports this, I would very much > >>>> appreciate any thoughts on how I could either modify any of the existing > >>>> packages to support this, or any external library for which it would be > >>>> fairly straight forward to write a PDL:PP interface. Perhaps CERNLIB > >>>> MINUIT is a good option? Has anyone ever written a PDL interface to > >>>> this? > >>>> > >>>> Cheers, > >>>> > >>>> Rahman > >>>> > >>>> --__________________________________________________________ > >>>> Rahman Amanullah, +46 8 553 786 61 > >>>> Stockholm University ICQ: 62860758 > >>>> Stockholm Centre for Physics, 17d 50m E > >>>> Astronomy & Biotechnology 59d 26m N > >>>> > >>>> PGP/GPG key ID: 0x3C229C80 > >>>> > >>>> > >>>> > >>>> _______________________________________________ > >>>> Perldl mailing list > >>>> [email protected] > >>>> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > >>>> > >>> _______________________________________________ > >>> Perldl mailing list > >>> [email protected] > >>> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > >>> > > > > > > > -- __________________________________________________________ Rahman Amanullah, +46 8 553 786 61 Stockholm University ICQ: 62860758 Stockholm Centre for Physics, 17d 50m E Astronomy & Biotechnology 59d 26m N PGP/GPG key ID: 0x3C229C80 _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
