TH1::Fit with option "I": setting integration precision


I want to fit a number of histograms with an option “I”. My fit function calculation is slow (it is a numerical integral of another non analytical function). So the fitting is very slow with the default “epsilon” (TF1::Integral parameter). Can I choose what value of “epsilon” should be used during fitting with the “I” option?

Or maybe there is some other way to control the numerical precision of integration when the option “I” is used during fitting?

I hope it is clear what I mean :slight_smile:

Thank you very much,
Siarhei. … tPrecision seems related.

Hello honk,

The function sets tolerance of minimization (i.e. chi2), not precision of integration during fitting. I am looking for how to set the later.

Thank you,