Fitting a simple peak

In this first example, there is no background and the peak can be fitted to a simple shape. The solid line is a Gaussian fit to the recorded peak.

Fit parameters:
Area of Gaussian = N, the number of counts in the peak.
s = sample standard deviation of the counts.
Gaussian peak position P_g=centroid of counts.

The quality of the fit can be obtained by examining the chi squared distribution (C²).

Vary the parameter P_g and see how C² changes.

The uncertainty in P_gcan be estimated from a full plot of C² against P_g (next)