Special instructions to install MLANP v.1.5.0 or other versions on MAC. The problems are given by the  the package Rpanel and bwidget tools, used for some interactive teaching tools; maybe in a future version I will change such interactive tools, because Rpanel often caused problems.

1. Close RStudio or R

2. Find on the web the bwidget tarball file (without installing it). My version is "bwidget-1.9.14.tar"

3. Copy it on /usr/local/lib/ 
(e.g. from a terminal: sudo cp bwidget-1.9.14.tar /usr/local/lib/)

3. Open a terminal and then give the commands:

cd /usr/local/lib/
sudo tar -xvf bwidget-1.9.14.tar

5. Previous step should solve the error 
about Bwidget

6. Download XQuartz, install it and run it.

7. Open RStudio and then install Rpanel. Now it should work

8. Few users had problems, after installing rgl, because MLANP failed to load rgl.so, due to a wrong version of libGL.1.dylib, due to XQuartz. In this case a reinstalling of something must be done. The best thing is to follow the post: https://stackoverflow.com/questions/66011929/package-rgl-in-r-not-loading-in-mac-os/66127391#66127391

9. I did not really understood many of the things written above, but they WORK!