My question is not complicated but I don’t know if it has to do with innerworkins of ROOT.
I have a histogram to which I want to fit a function I defined. If I do
hist->Fit("trace")
I get some output. If then I do
gPad->SetLogy()
hist->Fit("trace")
the output is different and if I then change the scale manualy, with the mouse, over the pad and then do the fitting again I get yet another answer. From all these, the one that looks best is the last one. I noticed that in the first two cases it gave me a negative parameter (that would be responsible for a zero in the function that can’t happen in log scale) and in the last one the parameter is positive, as it should be. I also tried limiting the parameter with
func->SetParLimits(5,0,1e19);
What is happening that gives me all these different answers? I would just like to reproduce whatever happened the time it worked, but that is when I change the scale manually. I’d like to do it on a script.
Javier
P.s.: for the record, I’m attaching a file with the histogram and a file that contains all the instructions I made
logFitting.tar (10 KB)