Extra Setup and Installation for Mac

If you have a Mac and want to take advantage of parallelization for fast run-times, then you'll likely have to take some extra steps if your default compiler (clang on Mac) does not have OpenMP support. If you're on a Windows or Linux machine, no need to read further--you're already benefitting from OpenMP parallelization.

Table of Contents Install OpenMP Install Compiler with OpenMP support Set Default Compiler to gcc Install looperr

Install OpenMP

First, we will need to install OpenMP libraries. This can be done by running the following command in the Mac terminal:

brew install libomp

If you have any problems, you might have to install the Homebrew package manager.

Install Compiler with OpenMP support

The easiest way to get OpenMP support for looperr on a Mac is to change the default R compiler to gcc from clang. Before installing, we remove gfortran (fortran compiler) because brew install gcc will install its own version

rm '/usr/local/bin/gfortran'
brew install gcc

Set Default Compiler to gcc

We next create a Makevars file which sets the default C, C++, and Fortran compilers that R will use when compiling packages. In this case, we are setting the default compiler to gcc version 10. You can create this file "by hand" in the ~/.R directory but you might as well just create it in the terminal as follows:

mkdir ~/.R
touch ~/.R/Makevars
{
  echo VER=-10
  echo CC=gcc-10
  echo CXX=g++-10
  echo CXX11=g++-10
  echo CXX14=g++-10
  echo CXX17=g++-10
  echo FC=/usr/bin/gfortran
  echo F77=/usr/bin/gfortran
  echo CFLAGS=-mtune=native -g -O2 -Wall -pedantic
  echo CXXFLAGS=-mtune=native -g -O2 -Wall -pedantic
  echo F77="gfortran-4.8"
  echo FC="gfortran-4.8"
  echo FLIBS = ""
} >~/.R/Makevars

Install looperr

You are then ready to install looperr! From the R console, type:

devtools::install_github("harveybarnhard/looperr")