Dear root users!
I have a small question related to the GraphFitChisquare function which is the default fitting function to be used by the TGraph::Fit() function. I’m doing a simple fit of a function (ax + b(1/x)) to 5 experimental values with both x and y errors. When using the TGraph::Fit() function I get values for a and b that differ from my own calculations when using a Maximum Likelihood technique and the method of effective variance. How is this done by the GraphFitChisquare function if it is not done by the method of effective variance?