Fortran vs. C for numerical work

[Dan Salomon]

In article <BGLENDEN.90Nov21003342 at mandrill.cv.nrao.edu> bglenden at mandrill.cv.nrao.edu (Brian Glendenning) writes:
>
>It is often stated that Fortran is better than C for numerical work. I
>am interested in compiling both the standard list of such arguments
>and what any counterarguments might be.

Here are the reasons that FORTRAN has not been replaced by C:

 1) C is definitely for wizards, not beginners or casual programmers.
    Usually people who are heavily into numerical work are not hacker
    types.  They are mathematicians, scientists, or engineers.  They
    want to do calculations, not tricky pointer manipulations.
    FORTRAN's constructs are more obvious to use, while even simple
    programs in C tend to be filled with tricks.  Even the fundamental
    operation of reading input is tricky in C, as shown by the recent
    postings on scanf, gets, and fgets.

 2) FORTRAN is dangerous to use, but not as dangerous as C.  For
    instance, most FORTRAN compilers have subscript checking as an
    option, while I have never encountered a C compiler with this
    feature.  The ANSI standard for function prototypes will
    give C an edge over FORTRAN in parameter mismatch errors, but
    that improvement is relatively recent and not enforced yet.

 3) There is a large body of well tested mathematical packages available
    for FORTRAN, that are not yet available in C.  For example the
    IMSL package.  However, this situation is improving for C.

 4) FORTRAN still gives the option of using single precision floating
    calculations for speed and space optimizations, whereas C forces
    some calculations into double precision.

 5) Optimizers are a non issue, since FORTRAN optimizers can match
    C optimizers on numerical expressions.


The reasons that C should replace FORTRAN for numerical work:

 1) C allows recursive functions, whereas portable FORTRAN doesn't.
    Recursive functions can often solve a problem more clearly
    than iterative methods, even if they are usually less efficient.

 2) FORTRAN has no dynamic array allocation.  Although C has dynamically
    allocated arrays, they are not trivial to describe or allocate.
-- 

Dan Salomon -- salomon at ccu.UManitoba.CA
               Dept. of Computer Science / University of Manitoba
	       Winnipeg, Manitoba, Canada  R3T 2N2 / (204) 275-6682