Hello, I am fitting background data with polynomial + exponential model using ROOT::Fit, and I have older results of the same fit performed by Roofit. With very basic installation of ROOT, the parameters obtained with ROOT::Fit are different by 6% - 9% with respect to the original Roofit results. If I run ROOT::Fit with an instance of root compiled with Mathmore library, the difference is significantly smaller - of the order of 0.3%. The Roofit result remains unaffected regardless of whether Mathmore is included or not. I cannot figure out where the Mathmore could be interfering in ROOT::Fit, can someone please point me to the correct direction?
ROOT Version: 6.18
Platform: Centos 8