Mathmore affects result of ROOT::Fit, Roofit results unaffected

ROOT
,
1

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?

Please read tips for efficient and successful posting and posting code

ROOT Version: 6.18
Platform: Centos 8
Compiler: gcc

2

Hi

This could be due to the numerical integration algorithm, the default one in ROOT could have some problems in same case. The one in Mathmore instead is superior

Lorenzo

3

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.