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From: robert_dewar@my-dejanews.com
Subject: Re: Calculating SQRT in ADA
Date: 1999/03/30
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Date: 1999-03-30T00:00:00+00:00
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In article <36FFF83A.BE789C93@mitre.org>,
  "Robert I. Eachus" <eachus@mitre.org> wrote:
>    Robert, your memory is going as you are getting older.
> ;-)  In the
> sixties and seventies, there were some extremely
> atrocious
> implementations in language run-time libraries.  The
> worst horror was
> the URAND for the IBM 360 which caused dozens of
> peer-reviewed papers to
> be withdrawn.  But I also remember many trigonometric
> libraries which
> used polynomical approximations that were good to only
> six decimal
> places--even for double precision.

It would be nice to see chapter and verse cited for this
(perhaps this horrible behavioor comes from the Honeywell
compiler that you always like to cite even though it never
saw the light of day :-)

In fact the IBM trigonometric routines were excellent on
both the 7094 and the 360. Indeed it is from Hirondo Kuki
(I hope I remember the spelling right, this is from a long
time ago on the 7094) that I learned about how math library
routines were written.

I will say again, I *far* better trust library routines
written by someone who knows what they are doing (which
ever since 7094 days tends to be the case, given the high
standards set by HK), than routines written by people who
just don't know math stuff.

And please note, this discussion is about elementary
functions, your reference to URAND, though it reflects
your own particular interest in random number generation,
is not germane to the thread on square root!

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