Perceived merits of Fortran
In the comp.lang.fortran news group I posed the following question:
“Fortran is widely perceived as being a superior language for
numeric and scientific programming. What are the features and
aspects that make it so?”
There was quite a bit of discussion and many interesting points
Below I have collated responses together and have added further
commentary, some of which may be on point. I thought the
comments and points being made would be of interest.
Many thanks to all, and to Beliavsky, Brooks Moses, Michael
Prager, Charles Russell, and David Rowell in particular.
Perceived advantages related to Scientific programming
Fortran is widely perceived as being particularly efficient
for computationally intense scientific programs. (Proponents
of other languages often contest this claim.) In part the
reason is that a great deal of work has been done on
optimization by compilers, and in part the reason is that
Fortran has a number of features, e.g., no aliasing by fiat,
that enable a variety of optimizations.
- Legacy Code
There is a large body of legacy code, both applications
and libraries, mostly scientific and numerical analysis.
There are (or are felt to be) more resources for developing
numerical analysis in fortran than in other languages.
Fortran has a suite of intrinsic mathematical functions and
numerical modes. Thus complex arithmetic is built in and
supported, exponentiation is a language operator, there are
generic intrinsics for single and double precision, and the
trigonometric, exponential, and logarthmic functions are
intrinsics. For a number of reasons intrinsics are more
desirable than “standard” libraries – for the developer.
- Multi-dimensional arrays:
Multi-dimensional (MD) arrays are hard to do right in a
language. Many languages either do not provide them or else
provide seriously inadequate support. Some issues are that
MD arrays should be first class citizens, i.e., the
information (bounds and extents) about them goes with them.
Bounds should be relativizable, and subspace extents should be
naturally accessible. Usw.
Language features perceived to make programming more pleasant:
- Safe DO loops:
The loop variable is prohibited from being altered within
- Arrays lower bounds:
Array lower bounds are 1 by default. This is not entirely
a matter of religious conviction; 0 based indexing implies
storage offset orientation, and 1 based indexing implies
ordinal based orientation. More importantly arrays bounds
can be set as desired.
- End of line statement termination:
Fortran uses end of line statement termination. Studies
were cited that showed that end of line termination is less
error prone than semicolon termination/separation.
- Enclosing block statements:
Fortran uses enclosing blocks rather than blocks internal
to statements. This has minor advantages.
- Restricted pointers:
Fortran’s pointer handling requires that pointer targets be
declared as TARGET. This is safer than wide open pointers
and facilitates optimization.
- Bounds checking:
Array bounds check is normally available as a simple compiler
- Derived types:
The KIND mechanism (Fortran 90) and parameterized derived
types (Fortan 2003) solve problems with platform dependent
- Subroutines and functions:
Fortran (like many languages) has both subroutines and
This page was last updated April 1, 2007.