I am trying a composite function for fitting muon data obtained at ISIS. I do not understand what “NumDeriv” is and what does it mean for it to be true or false. There is no documentation regarding that.
composite=CompositeFunction,NumDeriv=true;name=ExpDecayMuon,A=0.259619,Lambda=0.0851644;(composite=ProductFunction,NumDeriv=true;name=MuH,A0=1.20046,NuD=0.00110003,Lambda=-4.75099,Sigma=0.619706,Phi=1.76129;name=ExpDecayMuon,A=3.1181,Lambda=4.20696)
moreover, after the fitting curve, I see that the errorbars are ‘NaN’ when you export results to table; why? For example, if you have a fitting function in the form AB + C, and you want to initially fit the data with only C, and later on turn on AB part. How to do that?
Thanks
using Mantid version 6.11.0 (23 Oct 2024) on Windows 11