From: Conrad Schneiker <schneik@...>
Date: 2001-01-27T04:48:22+09:00
Subject: [ruby-talk:9952] Re: smallest non-zero number (and other limits)

Bil wrote:

# is there a ruby method which gives the smallest non-zero number like
# that provided by limits.h in c?  e.g., something like the smallest
# number which when added to unity yields a number different from
# unity.

It's been 20+ years since I last looked into this sort of stuff, but I 
vaguely remember it involved many interesting and (initially) somewhat 
counter-intuitive features. Does anyone know offhand (with respect to the 
IEEE Binary Floating Point Standard and/or with respect the way/extent 
that C/Java/Python/Perl actually make use of it) whether the "smallest 
number which when added to unity yields a number different from unity" is 
different from the smallest number which when added to zero yields a 
number different from zero? Also, do any of the comparatively more 
standard/common numerical libraries make any use of denormilized numbers?

Conrad Schneiker
(This note is unofficial and subject to improvement without notice.)