Can anyone tell me what I am doing wrong here. I am trying to fit the peak outlined on the attached graphic. Using FitPanel, I try and fit a gaus+pol1. This works if I do it the old fashioned way (i.e from the command line fitting two functions added together) but not when I do it using the new graphical method in Root 5.14.
These are the fit parameters that are returned… as you can see the p0,p1,p2 (gaussian fit params) are all zero?
EXT PARAMETER APPROXIMATE STEP FIRST
NO. NAME VALUE ERROR SIZE DERIVATIVE
1 p0 -1.68819e-30 2.50246e-30 2.71383e-23 1.06035e+26
2 p1 0.00000e+00 3.83794e+01 -0.00000e+00 0.00000e+00
3 p2 0.00000e+00 6.77530e-02 -0.00000e+00 0.00000e+00
4 p3 2.66227e+02 2.50246e+00 -5.90857e-02 1.06036e-04
5 p4 -4.20642e-02 7.54772e-04 -8.21172e-06 3.51399e-01
I am using Ubuntu LInux , with Root v5.14.
Many thanks for any ideas as to what is going on here.