Dear ROOT experts,
I’m experiencing difficulties in using the createIntegral() function to integrate a custom p.d.f.
The p.d.f. is composed of a background and several peaks. The components are linked by scale factors a, b, c, … and the fit determines which part contributes how much to the data. This works fine.
In the end, I want to integrate the whole function and then set the scale factors consecutively to zero to isolate a single peak or the background and integrate that to determine the ratio of events in each peak.
And here the problems start: Obviously createIntegral() does not work as I think it does. I put together a minimal example with a RooGenericPdf and a toy formula that has no physical meaning. In this example, the integral is always the same although I change a and b between the calls to createIntegral().
What am I doing wrong?
Thanks in advance for your help,
Tobias
problemDemo.C (1.04 KB)