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Re: How the computer identify an NaN?

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Jens Thoms Toerring <jt@toerring.de> wrote:
> Heinrich Wolf <invalid@invalid.invalid> wrote:

> > "bert" <bert.hutchings@btinternet.com> schrieb im Newsbeitrag 
> > news:0e6e63f1-e63e-4e52-9db5-ec1807044878@glegroupsg2000goo.googlegroups.com...
> > ...
> > >> ex:
> > >> b_u = 3;
> > >> (b_u!=b_u) ==> 1, right?
> > >>
> > >> Have you tried?
> > >> I doubt that.
> > >>
> > > You should listen more carefully when
> > > people who have a complete understanding
> > > of some topic try to explain it to you.
> > >
> > > Where 'b' is a real, (b != b) is 1 or 0,
> > > depending strictly on whether the current
> > > value of 'b' is a NaN, or is not a NaN.
> > > --

> > pardon?
> > I noticed that b_u is a real which results in 3.0 by assignment;
> > Why should (3.0 != 3.0) result in 1? 

> You snipped the most relevant part of your own post, i.e.

> >>> If NaN won't equal to anything, any number will not equal to itself
> >>> either. I still do not understand b_u != b_u;

> and the statement made by "bert" was that

>    b != b

> evaluates to 1 if b is not-NaN (e.g. for b set to 3) but to 0
> if b is NaN (always assuming that IEEE floating point represen-
> tation is used).

Sorry, got that just the wrong way round

For b = 3      b != b     results in 0
For b = NaN    b != b     results in 1

                              Regards, Jens
-- 
  \   Jens Thoms Toerring  ___      jt@toerring.de
   \__________________________      http://toerring.de

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How the computer identify an NaN? fl <rxjwg98@gmail.com> - 2011-08-15 20:19 -0700
  Re: How the computer identify an NaN? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-16 04:33 +0100
    Re: How the computer identify an NaN? fl <rxjwg98@gmail.com> - 2011-08-15 21:45 -0700
      Re: How the computer identify an NaN? Robert Wessel <robertwessel2@yahoo.com> - 2011-08-16 00:45 -0500
      Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 08:51 +0200
        Re: How the computer identify an NaN? bert <bert.hutchings@btinternet.com> - 2011-08-16 02:01 -0700
          Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 13:04 +0200
            Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:28 +0000
              Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:31 +0000
                Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 14:08 +0200
              Re: How the computer identify an NaN? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-16 13:37 +0100
                Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 21:13 +0000
            Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 14:17 +0200
          Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 13:22 +0200
            Re: How the computer identify an NaN? Angel <angel+news@spamcop.net> - 2011-08-16 15:17 +0000
      Re: How the computer identify an NaN? James Kuyper <jameskuyper@verizon.net> - 2011-08-16 08:42 -0400
      Re: How the computer identify an NaN? Stephen Sprunk <stephen@sprunk.org> - 2011-08-16 09:25 -0500
      Re: How the computer identify an NaN? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-08-16 12:37 -0600
        Re: How the computer identify an NaN? Keith Thompson <kst-u@mib.org> - 2011-08-16 12:26 -0700

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