Greetings!
"Stavros Macrakis" <stavros.macrakis@verizon.net> writes:
> Barton reports that bfloat(float(8/9)) == bfloat(8/9), which is not the
> closest bfloat to float(8/9).
>
> Raymond explains that floattofp rationalizes the float first, and adds
> "I agree that there should be fuzz digits, but it is rather nice to see
> the bigfloat looks like an obvious extension."
>
> bfloat should not be in the business of guessing -- it should represent
> the precise float in question.
>
> I suspect that float.lisp is using floattofp uses fixfloat out of
> expediency -- a machine-independent way of putting a float in rational
> form before integer-decode-float was widely available and reliable.
>
> By the way, there are some bugs in older versions of fixfloat (my
> 588346, 789053) but apparently they have been fixed.
>
> Willis, Ray -- didn't we discuss all this over a year ago? I think the
> only reason we didn't convert to integer-decode-float at that time was
> that it was buggy in GCL. In GCL 2.5.0, (integer-decode-float 1.0)
> crashes (my GCL Support Request #101688 of Jan 2003) -- this is reported
> fixed now.
>
Just a confirmation:
$ gcl
GCL (GNU Common Lisp) (2.6.1) Fri Jan 16 17:06:35 UTC 2004
Licensed under GNU Library General Public License
Dedicated to the memory of W. Schelter
Use (help) to get some basic information on how to use GCL.
>(integer-decode-float 1.0)
4503599627370496
-52
1
>
> -s
>
> _______________________________________________
> Maxima mailing list
> Maxima@www.math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>
>
--
Camm Maguire camm@enhanced.com
==========================================================================
"The earth is but one country, and mankind its citizens." -- Baha'u'llah