These commands are all from within Matlab. They demonstrate that Matlab (or GNU Octave) MEX C / C++ compiler wrapper is working on your system.
Using the Matlab example to your home directory with homepath.m
in Matlab or GNU Octave compile the callable C-code by:
use the compiled C-code function from Matlab or Octave by:
ans = 2.0000 5.9924 1.0000 2.986
if you get missing compiler errors, do Mex setup