[thebelal]

While it is true that S was originally a macro layer around FORTRAN code R has always been primarily written in C. Very little of R core is in FORTRAN, and essentially none of it is C++.

The language statistics show a good deal of FORTRAN (%24.5) [0], however that is largely skewed by the included LAPACK code [1], which accounts for 221,921 / 259,773 lines of FORTRAN in R.

[0]: https://github.com/wch/r-source [1]: https://github.com/wch/r-source/tree/trunk/src/modules/lapac...

[cat199]

> however that is largely skewed by the included LAPACK code

which is where most of your number crunching will be happening..