Hello. With 6.10/08, today I typed in the terminal: f = new TF1("f","gaus(0)",-20,20) f->SetParameters(0.13,5.4428,0.01) f->Mean(-20,20) (double) 5.632071 //!! f->Mean(-10,10) Error in <TF1::Moment>: Integral zero over range (double) 0.000000 f->SetNpx(1e6) //Hoped this would increase accuracy of T…

What concerns “intergration”, see for example: [image] Wrong convolution of 2 functions ROOT I blame the ROOT’s “Integral” method, so try with FWHM=10 …

I see. I suspected someone else already had to ask this, but I wasn’t able to find it by searching (we all start from different problems, it seems). Thank you for the references! (the big green grinning face as preview is lovely) In particular I copypaste for future readers: ROOT::Math::Integrator…

How to get accurate TF1::Moment()

ROOT

Wile_E_Coyote November 21, 2017, 2:59pm 2

What concerns “intergration”, see for example: