Re:Why physicists still use Fortran (2015)
by quadruplebond on Sunday October 15, 2017 @06:32PM
(#15479709)
I don’t use Fortran but I agree as of today and probably post 90 Fortran is nice enough but people moved to c++ for things like polymorphism and templates and pointers among other things. You could probably also rewrite nwchemex in Modern Fortran just fine. I’ll give you one example of why C++ might be easier though. Next gen linear algebra libraries are being written in c/c++ such as elemental and dplasma also Cyclopes tensor framework and probably others. When the libraries you want to use are in c/c++ the that can be the easiest path forward.
So why is NWChem being re-written in C++, and what relationship does that have to exascale? Richard O'Keefe said 10 years ago ago "Why not start by rewriting the Fortran code _in_ Fortran? Fortran 90 is a very pleasant language." (NWChem is just in Fortran77 as far as I remember.)
I work in HPC, though I don't write numerical code these days, but I'd definitely prefer to write it in Fortran than C, and I'm not clever enough to use C++. I'd also much rather maintain typical scientific Fortran.