Hi, The number to observe is the ratio between the data and the integral of the fitted Gaussian. You would like this number to be close to 1. A good starting point is to choose binning in your histogram such that sigma >= 1.5 bins . The value of chisq/ndf has an expectation value of 1 but is not a good indicator for bin size. Deviations from 1 are more likely from the data not following Gaussain statistics. Eddy --- Venkatesh Kaushik <venkat@hepmail.uta.edu> wrote: > Hi ROOTers, > i have a simple question. I have a set of data which > i know is nearly > gaussian, and i would like to plot the histogram. > what i don't know is how am i going to decide on the > number of bins and > the limits for defining a TH1F histogram object? > > i know if you change the number of bins the mean > value and the width of > gaussian varies. i need to be able to get a good > mean value and a good > value close to 1 for chisq/ndf if i fit a gaussian. > any comments or > readily available code? >
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