This example demonstration will show how to proceed to fit the peaks profile
in a particular range of a diffraction pattern. This profile fitting procedure
uses pseudo-Voigt functions with a global FWHM (Full Width at Half Maximum) and
a global eta (lorentzian proportion), and a linear background. Each peak is then
characterized by its angular position, intensity, FWHM and eta shifts with respect
to the global parents.
The data file in this example corresponds to a neutron diffraction pattern of
a powdered PbSO4, recorded on the D1A diffractometer at ILL, in the frame of
a Rietveld Refinement Round Robin (R.J. Hill, Journal of Applied
Crystallography 25 (1992) 589).
'File' / 'Open data file' opens a dialog box to select
the format of the data file we want to open.
