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Date: Fri, 2 Dec 2011 14:33:43 +1100 (EST)
From: Ian Smith <smithi@nimnet.asn.au>
To: Alexander Best <arundel@freebsd.org>
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Cc: freebsd-wireless@freebsd.org
Subject: Re: comparing floating points via "==" or "!="
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On Thu, 1 Dec 2011, Alexander Best wrote:
 > On Wed Nov 30 11, Igor Mozolevsky wrote:
 > > On 30 November 2011 22:44, Alexander Best <arundel@freebsd.org> wrote:
 > > 
 > > > i played a bit with the gcc -Wfloat-equal warning and noticed that inside
 > > > sys/dev/ath/ath_rate/sample/tx_schedules.h, a lot of comparisons of floating
 > > > points are happening ("=="). is there a better way to deal with this?
 > > 
 > > as opposed to (abs(a-b) < tolerance)?
 > 
 > fabs(3) actually, or some other way, e.g. described in:
 > 
 > http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm

Bookmarked, thanks.  Very good article, and I never knew IEEE floats 
could be compared as integers!  OT for wireless, but very useful for 
some astronomical stuff I'm working on .. in Pascal, no less :)

cheers, Ian