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Why Scientists Are Still Using FORTRAN in 2014
New submitter InfoJunkie777 (1435969) writes "When you go to any place where 'cutting edge' scientific research is going on, strangely the computer language of choice is FORTRAN, the first computer language commonly used, invented in the 1950s. Meaning FORmula TRANslation, no language since has been able to match its speed. But three new contenders are explored here. Your thoughts?"
1) Modern Fortran is not all uppercase ....
2) Modern Fortran does not have to start on column 7
3) Modern Fortran has dynamic memory allocation
4) Modern Fortran can use the same types as C (maximizes interoperability), hence can be called where C might be called
5) Modern Fortran has an objects, polymorphism, etc.
6) Modern Fortran has (a limited form of) pointers
7) Modern Fortran has concise array/vector/matrix operations
8) Modern Fortran has dynamically allocatable, multidimensional arrays that can be indexed starting with any integer
8) Modern Fortran supports the complex type without higgery-jiggery
9) Modern Fortran doesn't *need *pointers *in *all *the *places *that &C does, pass by reference is the norm
10) Modern Fortran is blazingly fast and designed for sciene
Some folks still write in Fortran 77, and the tired tales of woe that are bound to come from a language specification that is many decades old.
But, that code/style still works, and who am I to judge how you want to get your work done?
No, not just "legacy code." Fortran (yes, that's how it's spelt now, not "FORTRAN") was designed to be highly optimizable. Because of the way Fortran handles such things as aliasing, it's compilers can optimize expressions a lot better than other languages.
A: Legacy code, and because Fortran 2003+ is a very good modern language for scientific computation and maps very naturally to problems. As it turns out, the language semantics (both legacy and modern constructs) make it very good to parallelize. And it runs fast, as in, equalling C++ level of performance is considered a weak showing.
If you haven't seen or used modern Fortran and think it's anything like Fortran 66/77 then you're mistaken. Except for I/O, which still tends to suck.
In addition there are still some seemingly trivial but actually important features which make it better than many alternatives (starting from Fortran 90).
There's some boneheaded clunkers in other languages which Fortran does right: obviously, built-in multi-dimensional arrays, AND, arrays whose indices can start at 0, 1 (or any other value) and of course know their size. Some algorithms are written (on paper) with 0-based indexing and others with 1-based and allowing either one to be expressed naturally lowers chance of bugs.
Another one is that Fortran distinguishes between dynamically allocatable, and pointers/references. The history of C has constrained/brain-damaged people to think that to get the first, you must necessarily take the second. That doesn't happen in Fortran, you have ALLOCATABLE arrays (or other things) for run-time allocation of storage, and if you need a pointer (rarer) you can get that too. And Fortran provides the "TARGET" attribute to indicate that something *may be pointed to/referenced*, and by default this is not allowed. No making pointers/references to things which aren't designed to be referred to multiple times. This also means that the aliasing potential is highly controlled & language semantics constructed to make Fortran able to make very aggressive, and safe, optimization assumptions.
The more parallel you want, the more of these assumptions you need to get fast code, and naturally written Fortran code comes this way out of the box than most other languages.
This is absolutely right. It's also easier to write, in many cases. Most scientific applications don't need things like lambda expressions or derived classes. Many people who write applications as tools in their research don't want to spend time learning esoteric aspects of languages.
The big thing Fortran has over C is proper support for multidimensional arrays, with powerful slicing operations built into the language. It was the inspiration for numpy arrays. My first languages were C++ and C, but when I do scientific programming, my languages of choice are now python and fortran (with f2py making it very easy to glue them together). Fortran is horrible at text processing, and has an almost absent standard library, but for scientific use, good arrays make up for that - especially when you can use python in the non-performance-critical parts.
C++ has some multidimensional array classes, but none of them are as convenient as fortran arrays. Especially when it comes to slicing. At least that's how it was the last time I checked.