On Sun, 2025-02-16 at 16:59 +0000, Chuck Guzis via cctalk wrote: > CALGO ever since the beginning has also allowed algorithms in > FORTRAN, > it being the only language a lot of number-heavy shops use (e.g. > JPL).
The JPL suite of navigation software — orbit and trajectory determination, trajectory planning, … — started out in FAP and IBMAP on IBM 709 and 7090 and 7094 computers. It was converted to Fortran by about 1966. It eventually grew to more than sixty programs, encompassing about six million lines. In the mid 1990's a middle manager got a wasp up his ass and decreed it all had to be re-written in C++. I urged them to study Les Hatton's measurements that the average C++ program cost six times more during its entire life cycle than an equivalent program written in Fortran, C, or Ada. They did it anyway. They asked for 120 work years of funding. Fifteen years later they said "we're about 90% finished. We have a few loose ends. We only need another 120 work years of funding." It was used side-by-side with the legacy code for the Phoenix Mars lander. One of the navigators whispered to me "It doesn't work!" Instead of the original ODP (Orbit Determination Program) name, it's now called MONTE (Mission analysis, Operations, and Navigation Toolkit Environment). It works now. There's a python program that's helpful for preparing its input. Of course, that program is called MONTE Python. The Fortran-based ODP was maintained by a staff of 6.5 full-time equivalent. The MONTE staff is more than thirty. The Fortran standard has remained under development. FORTRAN 66 was the first language standardized by ANSI. Since then, standards were published in 1977, 1990, 2003, 2008, 2018, and 2023. A revision is under development. Intel provides free compilers for Windoze and Linux. The GNU compiler — gfortran — is available for many programs, but has an "interesting" definition of standard conformance. Sun offered a free compiler, but that got the axe when Oracle bought Sun. NVidia offers a compiler that includes CUDA extensions. And of course Cray (now part of HP/E) has one.
