[seqfan] Re: Maple strongly discouraged

[M. F. Hasler]

Even though I made that little bit sarcastic & exaggerated remark, I don't
think that Maple should be discouraged and even less that Mathematica
should be preferred.
It is somehow normal that a language evolves, and maple has in general
quite good downward compatibility, the RETURN() function is a noticable
exception. (Did never understand how they came to think about "RETURN()"!)
Other languages, the (younger) PARI included, have the same or worse
issues...
The name of the programming language should (et least optionally) include
the version, e.g. Maple V, Maple 10, PARI 2.6, PARI 2.6.1..., as I already
suggested earlier (and I even put (PARI 2.6.1) instead of (PARI) in some
submissions but this was not (always(?)) approved....)

Even mathematics changes definitions, e.g. for the primes...

I we are to make amendments in "code" sections, I'd vote for uniformization
and abolish the privilege of %m and %M tags for Maple and Mmca,
and/or find 1-2 more tags for the most popular progamming languages
(I think PARI is no more much behind %m and %M)
and/or implement a display routine that displays %o lines starting with
(BASIC) or (PHP) or (PARI 2.6) or the like as
<tr><td> PARI v. 2.6<td >Axxx = n -> ...</tr>
instead of
<tr><td> PROGRAM<td >(PARI v. 2.6) Axxx = n -> ...</tr>
since the latter is less easy to copy-paste.

M.


On Sun, Jan 12, 2014 at 2:07 PM, Neil Sloane <njasloane at gmail.com> wrote:

> Dear Seq Fans, Maximilian Hasler has pointed out that
> my Maple program in A109671 (which worked correctly in Maple 16)  no
> longer gives correct results in Maple 17 because it used the RETURN()
> command.
>
> The Maple web site says
>
> "use of the RETURN procedure is strongly discouraged"
>
> and I can see why - it produces incorrect answers (without any warning). Of
> course I don't see WHY they did this.
>
> Now there over 1900 Maple lines in the OEIS that use the RETURN statement.
>  Maybe these lines need a comment saying:
>
> # Warning: May give incorrect answers because Maple has changed the meaning
> of RETURN. Suggest switching to Mathematica instead.
>
> (Not sure about the second part)
>
> I could (and probably will have to) do this with a global edit.
> Is there any other solution?  It is unethical for us to include programs
> that give wrong answers.
>
> Here's the Maple program that works correctly in Maple 16 but gives wrong
> answers  in Maple 17:
>
> > f:=proc(n) option remember; local t1;
>
> > if n = 1 then RETURN(1);
>
> > elif n mod 2 = 0 then RETURN(f(n/2));
>
> > else t1:= f(n-2)-f((n-1)/2);
>
> > if t1 > 0 then RETURN(t1) else RETURN(f(n-2)+f((n-1)/2)); fi; fi; end;
>
> Neil
> --
> Dear Friends, I have now retired from AT&T. New coordinates:
>
> Neil J. A. Sloane, President, OEIS Foundation
> 11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
> Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
> Phone: 732 828 6098; home page: http://NeilSloane.com
> Email: njasloane at gmail.com
>
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>



-- 
Maximilian