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From: "David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>
Subject: Re: Calculating SQRT in Ada
Date: 1999/03/26
Date: 1999-03-26T00:00:00+00:00	[thread overview]
Message-ID: <FgzqKX3d#GA.202@pet.hiwaay.net> (raw)
In-Reply-To: 19990325232830.01123.00000079@ngol02.aol.com


John Herro wrote in message
<19990325232830.01123.00000079@ngol02.aol.com>...
>Robert Dewar said:
>> The proper way for testing for convergence is to see if
>> the new guess is the same as the last guess!
>
>Hans Marqvardsen said:
>>>   while X /= 0.0 and then
>>>        abs(Guess*Guess/X - 1.0) > 3.0*Dummy'Epsilon loop
>> Where does the multiplier 3.0 come from?
>
>There are some cases where the loop will alternate between two guesses, so
>testing that the new guess is the same as the last guess won't guarantee
>convergence with every implementation.  However, it might be possible to
>terminate when the guess is the same as EITHER the last guess OR the
>second-to-last guess.  I can't prove to myself that the loop would always
>terminate in this case, but it seems likely that it will.
>
John -- Did you look at my convergence test? It always works.






  reply	other threads:[~1999-03-26  0:00 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1999-03-24  0:00 Calculating SQRT in ADA cmcrae
1999-03-23  0:00 ` Chris Morgan
     [not found]   ` <36F913E0.75F51763@lmco.com>
1999-03-24  0:00     ` John Herro
1999-03-24  0:00       ` Hans Marqvardsen
     [not found]         ` <36FAA3DF.42C31CF@lmco.com>
1999-03-26  0:00           ` Tom Moran
1999-03-25  0:00       ` robert_dewar
1999-03-25  0:00         ` John Herro
1999-03-24  0:00           ` Hans Marqvardsen
1999-03-25  0:00             ` David C. Hoos, Sr.
1999-03-25  0:00           ` robert_dewar
1999-03-25  0:00             ` David C. Hoos, Sr.
1999-03-26  0:00               ` Howard W. LUDWIG
1999-03-26  0:00             ` Ole-Hjalmar Kristensen
1999-03-27  0:00               ` robert_dewar
1999-03-29  0:00                 ` Robert I. Eachus
1999-03-30  0:00                   ` robert_dewar
1999-04-02  0:00                     ` Robert I. Eachus
1999-03-30  0:00                   ` robert_dewar
1999-04-02  0:00                     ` Robert I. Eachus
1999-04-03  0:00                       ` robert_dewar
1999-03-25  0:00           ` robert_dewar
1999-03-26  0:00             ` Calculating SQRT in Ada John Herro
1999-03-26  0:00               ` David C. Hoos, Sr. [this message]
1999-03-26  0:00                 ` John Herro
1999-03-25  0:00       ` Calculating SQRT in ADA robert_dewar
1999-03-24  0:00     ` Ada 83 - Sometimes still chosen Richard D Riehle
1999-03-25  0:00       ` robert_dewar
1999-03-25  0:00         ` Richard D Riehle
1999-03-25  0:00           ` Larry Kilgallen
1999-03-26  0:00           ` robert_dewar
1999-03-26  0:00             ` Tom Moran
1999-03-26  0:00             ` Richard D Riehle
1999-03-26  0:00               ` Tom Moran
1999-03-26  0:00                 ` Larry Kilgallen
1999-03-29  0:00                 ` Marin David Condic
1999-03-29  0:00                   ` Tarjei Tj�stheim Jensen
1999-03-27  0:00               ` Matthew Heaney
1999-03-26  0:00             ` Tarjei Tj�stheim Jensen
1999-03-27  0:00               ` robert_dewar
1999-03-27  0:00                 ` Tarjei Tj�stheim Jensen
1999-03-25  0:00       ` robert_dewar
1999-03-25  0:00         ` Richard D Riehle
1999-03-25  0:00           ` Marin David Condic
1999-03-26  0:00           ` robert_dewar
1999-03-25  0:00     ` Calculating SQRT in ADA robert_dewar
1999-03-24  0:00       ` Howard W. LUDWIG
1999-03-25  0:00         ` Larry Kilgallen
1999-03-24  0:00   ` Marin David Condic
1999-03-24  0:00 ` bob
1999-03-24  0:00   ` Niklas Holsti
1999-03-26  0:00     ` bob
1999-03-26  0:00     ` als0045
1999-03-26  0:00       ` als0045
1999-03-26  0:00 ` Marin David Condic
1999-03-26  0:00   ` David C. Hoos, Sr.
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