Fortran vs C++ vs. etc (has little to do with realtime anymore)

[Jeffrey Templon <templon@studbolt.physast.uga.edu>]

"Igor Chudov @ home" <ichudov@algebra.com> writes:

> Brian Thomson <thomson@vnet.ibm.com> wrote:

> * a FORTRAN optimizer knows that A and B cannot be modified by the

 [ ... ]

> * In C++ there is no such guarantee (unless you supply one
> * outside the language via a #pragma), and it makes a noticeable
> * difference in these matrix algorithms that are a big part of
> * scientific programming.
> 
> Well, the programmer of a Matrix class has to know what he is doing.
> Making C++ code efficient may be harder than writing efficient fortran
> code, but it is not impossible.

This is a good point, but perhaps not in the way that Igor intended.
One of the main reasons I tend to push Fortran (or something similar,
like Ada or Python ... although maybe not everyone would see what
I mean by "similar" here ;-) is that with stuff like C++, you *do*
have to know what you are doing, or you will make a mess of it.
The fact remains (and will for some time) that many scientific programmers
are scientists FIRST and programmers SECOND.  Turning the average
physicist/programmer (at least in my field) loose with a C++ compiler
is like giving your car keys to your eight-year-old.  A few of
them would actually be able to drive, but most of them would cause
big damage trying.

So one of my reasons for Fortran still being around: you can write
a reasonable program which runs reasonably efficiently just by more
or less typing in an expression of a simple algorithm.  Fortran's "mental
model" of the computer is very simple.

						JAT