Re: The answer to "Can Ada replace FORTRAN for numerical computation?

[Brad Moore <bmoore.ada@gmail.com>]

On Sunday, July 21, 2019 at 10:38:16 PM UTC-6, Nasser M. Abbasi wrote:
> In 1980 there was a paper titled "Can Ada replace FORTRAN for numerical computation?"
> 
> ACM SIGPLAN Notices
> Volume 16, Number 12, December, 1981
> 
> 
> https://dl.acm.org/citation.cfm?id=954264
> 
> "
> In July 1980, the proposed final form of the Ada programming
> language was released by the U.S. Department of Defense [1]. Even
> though Ada was not designed specifically for general numeric
> scientific computation, nevertheless the question arises to whether
> it is appropriate for this purpose. This question can best
> be answered by consideration of the following question: Is Ada
> a suitable replacement for the programming language FORTRAN? This
> paper discusses those constructs of Ada which are pertinent to the
> matter and are considered defective. It is noted that the array defects
> are exceptionally critical, not providing needed capabilities
> that exist in FORTRAN and have been extensively used for
>   a quarter century."
> 
> I can't find free version of the paper, any one knows of one? but
> there was more discussion on it here:
> 
> https://archive.org/stream/DTIC_ADA139224/DTIC_ADA139224_djvu.txt
> 
> (just search for string "can ada")
> 
> _But_ to answer the question in the title of the paper, and
> after FORTY years, it is clear now that the answer is a
> resounding NO.

If the goal was to have Ada replace Fortran, that was never a realistic goal to begin with, for many reasons. One being that there exists a lot of legacy Fortran code out there, and secondly I cannot think of any cases where language X replaced language Y. There will likely always be supporters existing for language Y, expecially if it better fits a particular niche.

> 
> Too bad, because Ada could have been best language for numerical
> computation due to its strong typing. But its lack of support
> for many things related to linear algebra and such, as discussed
> in the above, Ada could not replace Fortran.

That being said, a lot has happenned to Ada since Ada 83, when those articles were written, including support for things like linear algebra and such. See Ada.Numerics.Generic_Real_Arrays and Ada.Numerics. Ada.Numerics.Generic_Complex_Arrays, which include routes to Solve matrices, and perform various other operations on them.

e.g.

    --  Real_Matrix inversion and related operations

   function Solve (A : Real_Matrix; X : Real_Vector) return Real_Vector;
   function Solve (A, X : Real_Matrix) return Real_Matrix;
   function Inverse (A : Real_Matrix) return Real_Matrix;
   function Determinant (A : Real_Matrix) return Real'Base;

Brad