Integrating a function using TF1

Newbie
1

I am trying to plot a function f(t)=f1(t)/f2(t) where f1 is a gaussian and f2 contains an integral. How can I use TF1 to integrate the following function from 0 to t:
a*exp(-0.5*((x-280)/10)**2)) dx

Thank you

2

Looks like you wanted to play with: TMath::Erf((t - 280.) / 10. / TMath::Sqrt2())

E.g., the integral from “-infinity” to “t”:
a * 10. * (TMath::Erf((t - 280.) / 10. / TMath::Sqrt2()) + 1.) * TMath::Sqrt(TMath::PiOver2())

3

Yes exactly! Thank you so much for your help.

5

Is the 10, sqrt (piover2) added because we did a change of variable in the integral, or was it to cancel out the factors of the normal distribution? and why did we add the 1?

Thank you