Fitting a distribution with two ranges

[dsahoo]

Dear Experts,

I want to fit the Bsmass(plot is attached). I want to fit it by double gaussian, exponetial and linear polynomial. Double Gaussian range: 5.1- 5.6
exponetial function: 4.7-5.6
linear polynomial : 4.7-5.1
Could you please suggest me how to fit it?

Thanks,
Deepak

[Wile_E_Coyote]

${ROOTSYS}/tutorials/fit/multifit.C

[yus]

Hi Deepak,

there is a nice documentation for this kind of problem:
https://root.cern.ch/root/htmldoc/guides/users-guide/ROOTUsersGuide.html#fitting-multiple-sub-ranges

[dsahoo]

Dear Experts,

I tried to fit sub ranges, but it is giving error as “ERROR: component selection expression ‘poly’ does not select any components of p.d.f.” I am attaching the macro and plot. Here I am fitting 5.1-5.6 with double gaussian+linear polynomial and 4.7-5.6 with linear polynomial. Please have a look on it.

Thanks,
Deepakbmass_full.cc (5.9 KB)