Hi all
A stupid question.
I want to get the exact expression of the equation of the landau distribution in the ROOT fit gr1->Fit(landau,"R").
When I find in the file in this path
/Root/v5-23-02/math/mathcore/src/TMath.cxx
i find the function in the TMath.cxx
Double_t TMath::Landau(Double_t x, Double_t mpv, Double_t sigma, Bool_t norm)
But in this function contain the expression is puzzle me . I do not know
the meaning of this sentence:
Double_t den = ::ROOT::Math::landau_pdf( (x-mpv)/sigma );
And I can not find the landau_pdf in the file Math.h
So can anyone kindly tell me the exact expression of the landau function?
And the fit par[n] location in this expression.
Like gauss funtion form:
f(x)= par[1]*exp(1/par[3] *(x-par[2])^2) where the par[n] is the fit
parameter
Best regard,
Fengchu
Received on Thu Oct 15 2009 - 13:39:06 CEST
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