From: Jim Freeze <jim@...>
Date: 2003-04-18T10:26:52+09:00
Subject: Re: Roundoff problem with Float and Marshal

On Friday, 18 April 2003 at  8:28:05 +0900, Rudi Cilibrasi wrote:
> nobu.nokada@softhome.net wrote in message news:<200304171653.h3HGrgHQ002407@sharui.nakada.kanuma.tochigi.jp>...
> > Since it was wrong a little, I fixed and committed it.
> 
> Hmmm interesting numerical developments.  I continue to test it by
> doing
> a cvs update (with and without the DBL_DIG patch) and do see perhaps
> some further problems:
> 
> 100000.times {
> w = rand(111111111)
> x = rand(222222223)
> y = rand(33333333334)
> z = rand(311414313)
> a = (x.to_f + y.to_f / z.to_f) * 
>   Math.exp(w.to_f / (x.to_f + y.to_f / z.to_f))
> ma = Marshal.dump(a)
> b = Marshal.load(ma)
> if a == b
>   puts "Everything is working fine for #{a}"
> else
>   puts "PROBLEM: a is #{a}, b is #{b}, and ma is #{ma.dump}"
>   puts "w is #{w}, x is #{x}, y is #{y}, z is #{z}"
> end
> }
> 
> produces many PROBLEM: lines on my system.

I hope your tests are being added to some set of unit tests
for ruby.

-- 
Jim Freeze
----------
It is the business of little minds to shrink.
		-- Carl Sandburg