Hi, Isard_Dunietz wrote: > 2) It also would be useful to calculate > the inverse > cummulative density function (c.d.f.), i.e. > the inverse fnct of > cdf( z ) = ( 1 + TMath::Erf( z / TMath::Sqrt(2) ) ) > Is such a fnct easily obtainable inside root? I once was looking for such a function, I didn't find it in ROOT. So I 'borrowed' inverse_normal_func(double p) and inverse_error_func(double x) from gnuplot's specfun.c. Looking at the copyright at the top of the file, it is not clear to me whether this could be included 1:1 into root.. Also, these functions seem to have their own copyright (the original fortran code called MDNRIS and seems to be from Netlib (www.netlib.org) -- however, I couldn't find it now) and one is only allowed to use them for non-commercial purposes... best regards, André -- ------------------+---------------------------------- Andre Holzner | +41 22 76 76750 Bureau 32 2-C13 | Building 32 CERN | Office 2-C13 CH-1211 Geneve 23 | http://wwweth.cern.ch/~holzner/
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