Hi pepe…I know that usually the lateral distribution of an EAS is described by the NKG function, so I tried to fit the data using this function (but the supervisor is on holiday, so I didn’t ask him if it is correct)…
I runned your macro and this is the result:
it looks like better than other macros…
what do you think about?
I will try the macro for other set of data too (I’ve 10 CORSIKA file, 5 files are EAS induced by photons and 5 files by protons)
Maybe your “analytical function” is not really describing your “experimental data” well (you would need to ask corsikans what function they are actually using).
Note that, for all your histograms, “bin_error” is something like 100 to 100000 times bigger than “bin_content” (I would expect the ratio “bin_error / bin_content < 1”).
Is it possible that these histograms were scaled, but Sumw2 was not called before making this operation?
Actually, I started to think that the main problem may be related to “bin errors” of all your histograms (which I pointed out in my previous post). Then the chi^2 is ridiculously small, which may fool the minimizer.
BTW. The current macro uses the same (fixed) “r_mol” parameter for all types of particles and I guess it’s not really completely right (but it depends on what was used by the one who produced this simulation). One could also try to fit “r_mol” (one simply needs to comment out the “FixParameter” line in the macro).