(...)
TGraphErrors * graph_llh = new TGraphErrors(nb_sa_histos, x, y, ex, ey) ;
(...)
graph_llh -> Fit("pol2") ;
(...)
How could I simply get the parameters in my program. Ican see them in the canvas using
gStyle -> SetOptFit(11) ; But I would like to make some calculus using the fit parameters.
Tnaks for the answer, I found such a trick in the ROOTmanual but it wasn’t working, Ijust forgot to include the TF1.h, anyway your mail helped me that the error was somewhere elese !