For mac you have to edit the file open /usr/local/Cellar/r/3.1.3/R.framework/Versions/3.1/Resources/etc/Makeconf and change clang++ to a compliler supporting openmp (like gcc-4.9)
For mac you have to edit the file open /usr/local/Cellar/r/3.1.3/R.framework/Versions/3.1/Resources/etc/Makeconf and change clang++ to a compliler supporting openmp (like gcc-4.9)