Re: Another little puzzle

From	Richard Heathfield <rjh@cpax.org.uk>
Newsgroups	comp.programming
Subject	Re: Another little puzzle
Date	2022-12-14 16:13 +0000
Organization	Fix this later
Message-ID	<tncsmt$2of9o$3@dont-email.me> (permalink)
References	(3 earlier) <tncjem$19kh$1@gioia.aioe.org> <tnclg3$2of9o$2@dont-email.me> <tncob5$1oat$1@gioia.aioe.org> <tncpgk$2of9h$7@dont-email.me> <tncqs4$uoe$1@gioia.aioe.org>

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On 14/12/2022 3:41 pm, Dmitry A. Kazakov wrote:
> On 2022-12-14 16:18, Richard Heathfield wrote:
> 
>>> BTW, averaging floats is a nasty problem too. A naive 
>>> implementation quickly loses precision.
>>
>> We're dealing with 'o'clock' and "HH:MM", and nowadays we have 
>> 64-bit integer types and there are even 128-bit integers 
>> mooching around looking for a reason to exist. You'd have to 
>> average a hell of a lot of times even to /need/ floats, let 
>> alone lose significant precision.
> 
> I never suggested float for averaging time stamps,

Yes, you did.

> I pointed out 
> that averaging is not a simple problem.

Yes, it is.

> E.g. try this one:
> 
>     function Average (X : Float; N : Positive) return Float is
>        Sum : Float := 0.0;
>     begin
>        for Index in 1..N loop
>           Sum := Sum + X;
>        end loop;
>        return Sum / Float (N);
>     end Average;
> 
> The function does naive averaging. For simplicity it just sums up 
> the same number X N times and divides by N.

You're not being naïve /enough/. The average of N instances of X 
is X, so just return X.

Yes, if you try hard enough, you can screw anything up. So what?

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within

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Re: Another little puzzle "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2022-12-14 14:06 +0100
  Re: Another little puzzle Richard Heathfield <rjh@cpax.org.uk> - 2022-12-14 13:10 +0000
    Re: Another little puzzle "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2022-12-14 14:35 +0100
      Re: Another little puzzle Richard Heathfield <rjh@cpax.org.uk> - 2022-12-14 14:10 +0000
        Re: Another little puzzle "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2022-12-14 15:58 +0100
          Re: Another little puzzle Richard Heathfield <rjh@cpax.org.uk> - 2022-12-14 15:18 +0000
            Re: Another little puzzle "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2022-12-14 16:41 +0100
              Re: Another little puzzle "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2022-12-14 16:43 +0100
                Re: Another little puzzle Y A <angel00000100000@mail.ee> - 2023-01-09 16:33 -0800
              Re: Another little puzzle Richard Heathfield <rjh@cpax.org.uk> - 2022-12-14 16:13 +0000
        Re: Another little puzzle V <angleeeeeeee@mail.ee> - 2023-05-10 11:16 -0700
    Re: Another little puzzle Ǝ <angel0000000001000000000000@mail.ee> - 2022-12-30 05:59 -0800

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