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Groups > comp.lang.c > #71378

Re: How to write this sign function in Delphi.

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: How to write this sign function in Delphi.
Date 2015-09-28 10:33 -0700
Organization None to speak of
Message-ID <lntwqesb25.fsf@kst-u.example.com> (permalink)
References (13 earlier) <muas3u$2bh$1@dont-email.me> <e9c6eb98-7324-4485-9b34-d004f0d09177@googlegroups.com> <muatrp$8kg$1@dont-email.me> <mub0oi$ije$1@dont-email.me> <mub51i$23e$1@dont-email.me>

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Richard Heathfield <rjh@cpax.org.uk> writes:
> On 28/09/15 10:22, Bartc wrote:
>> On 28/09/2015 09:32, Richard Heathfield wrote:
>>> On 28/09/15 09:24, Malcolm McLean wrote:
>>
>>>> Represent as 110 cents instead. 2^53
>>>> gives us 90 trillion dollars - uncomfortably close to Obama's
>>>> credit card amount outstanding.
>>>
>>> But you're not guaranteed 2^53 pennies. The Standard allows double to be
>>> as small as 32 bits.
>>
>> You'd be short-changed if you specified double and only got
>> single-precision. Anyway where does it say that in the Standard?
>
> The float type can be as small as 32 bits (it /is/ 32 bits on the system 
> I'm using right now) and the Standard does not require DBL_MAX to be 
> greater than FLT_MAX or for DBL_MIN to be lower than FLT_MIN, so 
> presumably it can fit into the same number of bits as a float.

Similar reasoning would imply that long can be as narrow as 16 bits.

The standard requires FLT_DIG to be at least 6, and DBL_DIG to
be at least 10.  Both FLT_MAX and DBL_MAX are required to be at
least 1E+37.

6 decimal digits is about 20 bits, and 1E+37 is about 2**123, which
implies you need about 7 exponent bits, so float needs to be about
28 bits or more.

10 decimal digits is about 33 bits, so double needs to be about 41
bits or more.

I've undoubtedly made one or more off-by-one errors above, but not,
I think, enough to permit double to be represented in 32 bits.

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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Thread

How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 20:17 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 20:43 +0200
  Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-21 19:51 +0100
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 23:26 +0200
      Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-21 22:47 +0100
        Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 16:29 +0200
          Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-22 16:11 +0100
            Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-23 11:18 +0200
              Re: How to write this sign function in Delphi. David Brown <david.brown@hesbynett.no> - 2015-09-23 13:01 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 20:53 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 20:54 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 20:58 +0200
    Re: How to write this sign function in Delphi. M Philbrook <jamie_ka1lpa@charter.net> - 2015-09-21 18:15 -0400
      Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-21 15:21 -0700
      Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-21 17:51 -0500
        Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-21 19:15 -0400
          Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-21 23:59 -0500
          Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-22 09:22 -0700
            Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-22 10:32 -0700
            Re: How to write this sign function in Delphi. jt@toerring.de (Jens Thoms Toerring) - 2015-09-22 18:17 +0000
              Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-22 12:25 -0700
                Re: How to write this sign function in Delphi. jt@toerring.de (Jens Thoms Toerring) - 2015-09-22 22:33 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-22 15:52 -0700
            Re: How to write this sign function in Delphi. raltbos@xs4all.nl (Richard Bos) - 2015-09-22 23:09 +0000
              Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-23 09:07 -0700
                Re: How to write this sign function in Delphi. Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-09-23 16:55 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-23 10:46 -0700
                Re: How to write this sign function in Delphi. jt@toerring.de (Jens Thoms Toerring) - 2015-09-23 23:18 +0000
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-23 22:29 -0400
                Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-24 11:09 +0100
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-27 18:23 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-28 05:20 +0000
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-27 23:23 -0700
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-28 09:03 +0100
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-28 01:24 -0700
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-28 09:32 +0100
                Re: How to write this sign function in Delphi. Bartc <bc@freeuk.com> - 2015-09-28 10:22 +0100
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-28 11:35 +0100
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-28 10:33 -0700
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-28 18:59 +0100
                Re: How to write this sign function in Delphi. Rosario19 <Ros@invalid.invalid> - 2015-09-28 20:09 +0200
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 13:39 -0500
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-28 20:04 +0100
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 16:43 -0500
                Re: How to write this sign function in Delphi. Martin Shobe <martin.shobe@yahoo.com> - 2015-09-28 18:55 -0500
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 19:31 -0500
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-28 12:16 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-28 14:31 -0700
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 16:47 -0500
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-29 11:54 -0700
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-10-01 00:36 -0500
                Re: How to write this sign function in Delphi. raltbos@xs4all.nl (Richard Bos) - 2015-10-02 10:53 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-02 09:48 -0700
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-10-03 11:27 -0500
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-03 12:32 -0700
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-10-03 11:26 -0500
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 16:46 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-28 14:23 -0700
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 16:52 -0500
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-30 01:39 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-30 12:37 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-30 21:28 +0000
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-30 17:54 -0400
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-01 03:59 +0000
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-10-01 01:42 -0400
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-30 16:20 -0700
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-04 16:39 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-28 23:23 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-29 09:35 -0700
                Re: How to write this sign function in Delphi. raltbos@xs4all.nl (Richard Bos) - 2015-10-02 11:06 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-02 09:23 -0700
                Re: How to write this sign function in Delphi. Martin Shobe <martin.shobe@yahoo.com> - 2015-10-02 12:07 -0500
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-02 10:47 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-10-02 17:48 -0700
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-10-03 16:46 +0100
                Re: How to write this sign function in Delphi. Martin Shobe <martin.shobe@yahoo.com> - 2015-10-05 10:41 -0500
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-28 15:31 -0400
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 16:40 -0500
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-28 18:17 -0400
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-30 02:49 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-30 06:27 -0700
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-29 10:43 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-28 22:51 +0000
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-30 02:11 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-28 22:48 +0000
                Re: How to write this sign function in Delphi. Robert Wessel <robertwessel2@yahoo.com> - 2015-09-28 22:03 -0500
                Re: How to write this sign function in Delphi. Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-30 01:13 -0700
                Re: How to write this sign function in Delphi. Bartc <bc@freeuk.com> - 2015-09-30 17:06 +0100
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-09-30 17:26 +0100
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-09-30 13:04 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-28 09:12 +0000
                Re: How to write this sign function in Delphi. David Brown <david.brown@hesbynett.no> - 2015-09-28 12:28 +0200
                Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-28 20:44 +0100
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-01 01:39 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-10-01 08:55 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-01 09:02 -0700
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-01 14:55 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-01 16:48 -0700
                Re: How to write this sign function in Delphi. raltbos@xs4all.nl (Richard Bos) - 2015-10-02 11:46 +0000
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-06 00:15 -0700
                Re: How to write this sign function in Delphi. Les Cargill <lcargill99@comcast.com> - 2015-10-06 02:43 -0500
                Re: How to write this sign function in Delphi. David Brown <david.brown@hesbynett.no> - 2015-10-06 10:13 +0200
                Re: How to write this sign function in Delphi. Les Cargill <lcargill99@comcast.com> - 2015-10-06 19:14 -0500
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-06 21:36 -0700
                Re: How to write this sign function in Delphi. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-06 09:25 +0100
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-06 09:28 -0700
                Re: How to write this sign function in Delphi. Keith Thompson <kst-u@mib.org> - 2015-10-06 13:11 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-06 13:56 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-07 00:25 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-06 09:44 -0700
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-06 10:08 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-06 12:00 -0700
                Re: How to write this sign function in Delphi. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-07 01:58 -0700
                Re: How to write this sign function in Delphi. Richard Heathfield <rjh@cpax.org.uk> - 2015-10-07 10:12 +0100
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-08 00:40 -0700
                Re: How to write this sign function in Delphi. Philip Lantz <prl@canterey.us> - 2015-10-03 12:29 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-03 13:20 -0700
                Re: How to write this sign function in Delphi. Philip Lantz <prl@canterey.us> - 2015-10-03 12:33 -0700
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-10-03 17:02 -0400
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-03 15:04 -0700
                Re: How to write this sign function in Delphi. glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-10-04 05:12 +0000
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-04 12:58 -0700
                Re: How to write this sign function in Delphi. Philip Lantz <prl@canterey.us> - 2015-10-03 12:37 -0700
                Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-10-03 16:21 -0400
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-03 16:05 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-10-03 14:02 -0700
                Re: How to write this sign function in Delphi. supercat@casperkitty.com - 2015-09-24 09:39 -0700
                Re: How to write this sign function in Delphi. raltbos@xs4all.nl (Richard Bos) - 2015-09-27 16:26 +0000
        Re: How to write this sign function in Delphi. M Philbrook <jamie_ka1lpa@charter.net> - 2015-09-21 22:06 -0400
          Re: How to write this sign function in Delphi. James Kuyper <jameskuyper@verizon.net> - 2015-09-22 10:17 -0400
            Re: How to write this sign function in Delphi. M Philbrook <jamie_ka1lpa@charter.net> - 2015-09-22 19:48 -0400
              Re: How to write this sign function in Delphi. Noob <root@127.0.0.1> - 2015-09-23 13:15 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 21:25 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 21:54 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 22:02 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-21 21:50 +0200
  Re: How to write this sign function in Delphi. M Philbrook <jamie_ka1lpa@charter.net> - 2015-09-21 18:08 -0400
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 08:31 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 10:18 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 10:50 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 11:00 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 11:07 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 11:20 +0200
  Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 11:15 +0200
    Re: How to write this sign function in Delphi. "Skybuck Flying" <skybuck2000@hotmail.com> - 2015-09-22 11:23 +0200

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