polyhedron.com · Domains · Slashdot Mirror

Fortran 90+ with OpenMP or Python by dlenmn · 2013-10-17 05:48 · Score: 1 · on Ask Slashdot: Best Language To Learn For Scientific Computing?

If you really want to do heavy lifting, you can't beat Fortran. Just stay away from Fortran 77; it's a hot mess. Fortran 90 and later are much easier to use, and they're supported by the main compilers: gfortran and ifortran.

ifortran is Intel's Fortran compiler. It's the fastest out there, and it runs on Windows and Linux. Furthermore, you can get it as a free download for some types of academic use. (Search around intel's website -- it's hard to find.) That said, I usually use gfortran -- which is free and open source -- on linux. See http://www.polyhedron.com/compare0html for a compiler comparison.

If you use Fortran, it's very easy to use OpenMP to do multiprocessing and make use of all those cores. OpenMP is supported by the main compilers.

If you're doing lighter work, SciPy/NumPy works fine; I use it a fair amount if maximum performance isn't essential. However, I can't speak to its multiprocessing ability.

Re:Welcome FORTRESS by Anonymous Coward · 2007-01-15 17:44 · Score: 1 · on Sun Releases Fortran Replacement as OSS

Clearly, you have no idea want your talking about. Fortran 66 became an ANSI
standard in March 1966. Fortran 77, the revision to F66, became an ANSI
standard in April of 1978. I don't have access to the Fortran 90 standard,
so can't post a date, but Fortran 95 was ratified in 1997 as an ISO standard.
Fortran 2003, the newest standard, became the standard in Nov. of 2004.
Work is currently underway on Fortran 2008. You can read about the details at
http://www.j3-fortran.org/ The fact that several vendors offered often
incompatible extensions isn't the fault of the various Standard committees.
Fortran, as a standardize language, has been around for over 50 years. You
can't say that about any other language.

As to Fortran in GCC. It is alive and well. You can go to http://gcc.gnu.org/ or
http://gcc.gnu.org/wiki/GFortran to learn more. You may also be surprised
that gfortran is competitive with commercially available compilers. See
compiler comparison at http://www.polyhedron.com/

C/C++ vs. Fortran by Aardpig · 2004-09-18 14:50 · Score: 4, Interesting · on Comparing Linux C and C++ Compilers

I find it interesting that there are only two C/C++ compilers available for Linux, as compared with seven Fortran 90/95 compilers (soon to be eight with the release of GCC 4.0). This not only dispels the myth that Fortran is a dead language, it also suggests that there is much more of a competitive market in compiling numerical code, than in producing other types of software.

Fortran compilers and Linux by EmagGeek · 2003-01-01 23:16 · Score: 4, Interesting · on Linux Number Crunching: Languages and Tools

Here is a more in-depth comparison of Fortran 90 compilers for linux. They compared Intel, NAG, Lahey, and a couple of other compilers. Here is a comparison of Fortran 77 compilers from the same folks. GNU g77 is actually the slowest of them all, and I've actually confirmed that it is the slowest of a group consisting of DEC/Win32, Lahey/Linux, and g77. I've always dreamed of the day that open source developers would throw some real brainweight at a really well optimized Fortran compiler for linux, but it looks like I'll just have to keep dreaming. Lahey is only $199 or so, but they place some HORRIBLE licensing restrictions on the binaries that are created with their compiler. The DEC/Win32 compiler is also really nice, but since I'm not in school anymore, I'm not licensed to use it, and even if I _wanted_ to whore myself out to Micro$oft, I couldn't afford to.

Just to put some things into perspective, here are some numerical results. These were obtained on my dual-athlon 1.4GHz w/ 1GB of RAM. The task was to compute the TE and TM surface currents induced on a circular cylinder 10 wavelengths in circumferece and having a relative permittivity equal to 4-j2. The program simultaneously solves the perfect electric conducting case. The surface was discretized into 60 cells using 120 unknowns (way overkill, but just to prove the point) using the Integral Equation Asymptotic Phase method.

g77 Compiler (-O2 -malign-double -funroll-loops): 24.11s
Lahey Compiler (equivalent paramters): 16.45s

As you can see, there's really no comparison, except that the lahey-created binary uses about 10% more RAM than does the one created with g77. This is just a summary comparison as I did not go into measuring the difference in the error of the two results compared to a reference solution. I'm assuming that both solutions are about the same with regard to accuracy.