xsl-list
[Top] [All Lists]

Re: XSLT 2.0 Decimal number silliness

2004-03-29 04:12:34
Jeff Kenton <jkenton(_at_)datapower(_dot_)com> writes:

I've been looking at XSLT 2.0 decimal numbers (again), and I still
think the WC needs to do better.
[...]
<xsl:value-of select="2.0 div 3.0" />~
<xsl:value-of select="0.444 div 0.666" />~
[...]
Both lines of output should be equal.

Why?  The majority of implementations will use a binary format such as
IEC 60559 to hold floating point numbers.  2.0 and 3.0 can be
converted exactly but the representations of 0.444 and 0.666 will be
inexact (0.44400000000000001 and 0.66600000000000004 in my test).  You
might get a better match with 0.5 div 0.75.  If you want fixed point
number semantics try moving the decimal points to the right before
dividing.

Floating point arithmetic is inexact by definition.  Your results
_are_ the same to within the precision specified by the language
and/or implementation.
-- 
Pete Forman                -./\.-  Disclaimer: This post is originated
WesternGeco                  -./\.-   by myself and does not represent
pete(_dot_)forman(_at_)westerngeco(_dot_)com    -./\.-   opinion of 
Schlumberger, Baker
http://petef.port5.com           -./\.-   Hughes or their divisions.