I’m trying to fit a resonance-curve and know the approximate magnitude of my parameters, but my function just does’nt want to fit. I had another set of data, which I got fitted after some trial & error, but with this, it just does not work. i tried fixing some, adjusting the range, and setting different initial values. any other suggestions or fundamental advice?
p1 sould be around 1e10, p2 around 1e3, the code is attached
ps: i run root 5.17 with ubuntu 7.10
nicht-lin_neu.txt (479 Bytes)
nicht-lin_neu.cpp (1.7 KB)
are you sure the definition of your function is correct ?
It looks to me a bit bizzarre. If I try to fit with a simple breit-wigner the fit works fine.
I would re-define your function and put for example as a parameter the location of the maximum.
we derived this function from general assumptions and it did fit for the first data set, so it should be the real one. anyway, i will check this, thanks for your hint