eugene@ames-lm.UUCP (Eugene Miya) (06/20/84)
Interesting discussion on physicists programming C and other things. Background: started with FORTRAN {eventually learned Pascal and C (latter is current preference) and Ada}. Currently programming on a Cray XMP in FORTRAN. I have principally used UNIX and other systems in scientific applications environments: image processing, simulation, and analysis. Personally, I think C is a better scientific language in many respects than FORTRAN. The complaints of all double precision being too slow fall on deaf ears here. We need the precision. When I worked at JPL, there existed a math group to get as many bits difference out of a 36 bit Univac word compared to a 32 bit IBM word (don't ask me why they didn't have a CDC, they could not afford a Cray). The loss of ** was not great-> pwr() and other means were preceived as safer and more efficient. What do you want, execution speed or Voyager I missing Saturn after a billion mile trip (by a couple million miles). FORTRAN is probably here to stay. Its modifability is reaching its end. Vectorization and multiple processes [parallelism] are added grudgingly. But, I would seriously doubt it would die. I have attended X3J3 [ANSI FORTRAN] meetings (and am a former member of X3J9 [Pascal standards]). You have to understand that huge (multi million line codes) were written in the 50s. These still need to run. Lots of industries still depend [Can you image a system like BART switching as hardware gets obsolete?] on FORTRASH [see two CACMs ago, a member of Huge Air Crash was pleading for 'the whipping boy of the CS community.' I think BTL's efforts for ratfor and efl are an quite interesting way to transition over to languages like C. Another thing I have started to notice is that the education of computer use has spread from CS, math, and EE depts to physics, chem, art and social science depts. In general, the physics and chem depts teach FORTRAN, the rest teach BASIC. FORTRAN is out of the hands of CS. What interests a lot of the old FORTRAN is the tools environment in UNIX. Brenda Baker's struct program, and other HLL->HLL translators interest a lot of people. To get some easy (but understandability crude) translator would help a lot of people out of the FORTRAN rut. Oh, adding this, APL: early implementations [inefficient] of APL killed that language for many users. I hear stories of row and rows of APL programmers back East in IBM. While APL was to have been a noble attempt, it is rarely traught in physics depts. Now, a system like UNIX which has APL, LISP, C and f77 under one roof at least gives people a chance to try new languages where may not be available on MVS or VMS. One office mate is just giving LISP a first try. Perhaps, APL will get a second wind. ***Here's the meat****** Lastly, no flame, I just received a copy of the User's Guide to C under COS. COS is the Cray Operating System. We are eagerly awaiting the Cray C compiler from Bell. We know it is not a fine tuned compiler, but our systems people prefer C over BLISS, and would love to have C on the XMP. I have only really run C extensively on PDP,VAX,68K environemnts. I have heard stories that on IBM C, there are some interesting architectural side effects. Briefly: C on the Cray: shorts are 24 bits, as are pointers. The sizeof macro has no meaning in this context. Longs and ints are 64 bits. It has the enum and void types as well as structure passing. Floats and doubles are both 64 bits (too bad), but the Cyber 180 also did this. There are lots of fast registers as well as a register float type. A few additional functions are added for vector copy operations. I really wonder what C on a Univac environment is like. Does any one have an Ada compiler for the Cray? Need I say more? In summary, FORTRAN is here to stay [too bad in some ways]. C (because of the pcc and pcc-2) has a good chance of making its way into scientific computing. Pascal lesser so. APL needs a second coming. --eugene miya NASA Ames Res. Ctr. {hplabs,hao,research,dual}!ames-lm!statvax!eugene
malcolm@ecn-ee.UUCP (06/22/84)
#R:ames-lm:-34800:ecn-ee:15000001:000:616 ecn-ee!malcolm Jun 21 19:59:00 1984 The best reason to use C instead of Fortran is the human interface. For my research I write large/long running number crunchers and an awful lot of the code is used to parse the command line arguments and check their sanity. True, C has some shortcomings (no complex!) but I'd much rather have the nice string and structure manipulation. Right now I am anxiously waiting for C++ to see the light of day..... Malcolm Slaney Nouveau Image Processing Lab Purdue EE Dept. P.S. Kuo Chen Li, here at Purdue, has defined and implemented a Vector C for the Cyber 205. It is real nice...and fast too.
steven@mcvax.UUCP (Steven Pemberton) (07/03/84)
> True, C has some shortcomings (no complex!) but I'd much rather have the > nice string and structure manipulation. C's string manipulation NICE???? Save me from languages with nasty string manipulation! Steven Pemberton, CWI, Amsterdam. steven@mcvax