Install rstan

Complete the following steps to install rstan on an Intel Mac running Big Sur (MacOS 11.6).


 * 1) Install Xcode or just the Xcode command line tools. For the command line tools, enter   in Terminal. Verify installation by entering.
 * 2) Install gfortran. Download the installer for your version of macOS here. Verify installation by entering   in Terminal.
 * 3) Set compiler optimizations in ~/.R/Makevars:
 * 4) Remove any existing rstan installations:
 * 5) Install rstan:
 * 6) Restart RStudio.
 * 7) Verify that rstan is working by fitting the eight schools example model.
 * 8) *Write the text below to a file named :
 * 9) *Create the dataset, fit the model, and do stuff with the fit: