Hi there, this is my first time on this forum. Nice to meet you.
I am facing a similar problem. I am trying to fit a TGraphErrors (18 pts) with a third order polynomial. The problem is that the fit is giving me a reduced chi square value of 22817.4.
In principle even a first or second order polynomial would give me a decent fit result, but the chi square would be even larger. The error bars a very small, that’s true. I also tried to artificially increase the error bars but it still gave me a huge number. If I remove the error bars and I use TGraph instead, I get 0.0402568.
What am I missing? What can I do to solve the problem?
Thank you very much in advance