Reflex 35 ---> reflex36
 - improvement of error messages
 - fixed a bug in the "irregular multilayer" section
 
 Reflex 36 ---> reflex37
  - fixed a bug which prevented saving and exporting the density profile
  - fixed a bug in "Show the changes" menu
  
Reflex 37 ---> reflex38
 - fixed bug which sometimes prevented saving a parameters file.
 
 Reflex38 ---> reflex39
  - fixed bug in multi-start with qc
  - fixed bug in slider about SLD/delta
  - fixed bug in previous/next parameters with delta/SLD
  
Reflex39 ----> reflex40
 -fixed bug in Add new material

Reflex40 ----> reflex41
  - fixed a bug which prevented saving and exporting the SLD profile for neutron reflectivity

Reflex41 ----> refex42
  - add the possibility to take in account the absorption for neutron reflectivity. Absorbent elements has been added in the database.
It is recommanded to replace the folder "databaseN" by the new one.

Reflex42 ----> refex43
X-rays and soft X-rays:
- better management of the nature of the layers that make up the sample.
- The name of the material which constitutes the layers is saved in the parameters.
- Look at database menu: possibility to change the wavelength / energy in the window.
Soft X-rays:
  - Look at database menu: display of Delta and Beta according to the energy.

Reflex43 ---->reflex44 (03/11/2020)
 -Add Evaluating Goodness of Fit : correlation matrix of parameters, representation of the sensitivity of the parameters,
Residual Analysis, R-square, Adjusted R-square, Root mean squared error (RMSE) ...

Reflex44 ---->reflex45 (26/10/2021)
(1) Link between qc/delta/SLD and absorption via density (there is now a button near the absorption. By pressing it, it becomes green and the link is made between the electron density and the absorption).
(2) Possibility to display the first derivative of the reflectivity curve.
(3) Possibility to enter the half width at half maximum (HWHM delta theta) of the direct beam for the resolution
(4) Better visibility of blocked parameters for fitting.
(5) Possibility to represent linear(R)*q4
(6) correction of the problem of normalization of the experimental curves by the intensity of the direct beam
(7) possibility to move the density profile graph on the reflectivity curve directly with the mouse
(8) improvement of "Print parameters" 


Reflex45----->reflex46 (10/01/2022)
- possibility to fit with a genetic algorithm to avoid local minimums
- possibility to fit autocorrelation function at the same time as the reflectivity curve

Reflex46----->reflex47 (05/07/2022)
 - fix a bug when a Normalization of the data was followed by a change theta to qz.

Reflex47----->reflex48 (21/09/2022)
  - It is now possible to fit a multilayer with a link between qc and and absorption via density.
  - improvement of the fit of the autocorrelation function

Reflex48----->reflex49 (26/10/2022)
 - Fixed a bug that prevented to fit a multilayer with SLD or electron density

Reflex49---->reflex50 (13/01/2023)
 -  correction of a bug during the reset of the neutron reflectivity data
 -  Improved management of the fit parameters when the SLD is negative (neutron reflectivity)
 -  Ability to save the default directory of data (all)
 -  Possibility to fit the autocorrelation function with the genetic algorithm
 -  new program to fit TOF reflectivity measurements
 
 Reflex50---->reflex51 (22/05/2023)
 - it is now possible to change the size of the parameters windows without stretching everything inside the window
 - When a part of the curve is zoomed, it is now possible to change the parameters while keeping the selected zoomed part of the curve
 - small improvement in the allocation of the preference directory
 - bug fixed : When the link between density and absorption was engaged, when trying to fit by the method "reflectivity + autocorrelation", the graphs do not update 
 
 Reflex51 ---->refelx52 (17/07/2023)
   - Parameters (roughness, density, thickness) can be correlated/linked between different layers.
     This function is useful when a multilayer is not perfectly regular. 
   - (XRR) Better management of the parameters window. Multistart bug fixed.
   - (All) Bug when estimating the quality of a fit with more than 10 layers corrected
   - (All) Add a mailto menu to send an email to the programmer
   - (All) Creation of a logfile to record error messages (MyLogfile.txt)
   - (XRR & Soft) Fixed a bug when replacing an already existing material in the database
   - (XRR & Soft) Improved interpolation of quantities near an absorption threshold
  
  Reflex52 ---->refelx53 (24/08/2023)
  - Fix a bug when loading data/paramters with a defined preference directory
  - The choice of beam shape (retangular or Gaussian) is saved and retained when reflex is started.