Re: ver 1.9.4 use more decimal digits

[bill lam <cbill lam gmail com>]

On Sun, 01 Mar 2009, Morten Welinder wrote:
> > After upgraded to 1.9.4. Diff the gnumeric file with the previous
> > 1.8.3
>
> This is deliberate.  We need to store enough decimals to ensure
> that the number we had will come back unchanged.  The number

This is incorrect. The number pairs have the same bit pattern using
ieee 754 standard so that they are equal. Merely adding more digits
does no increase the accuracy. There is an article by Kahn who is the
driving force behind the IEEE 754 standard, and he got the Turing
Award in 1989 for his work on numerical analysis.

How Java's Floating-Point Hurts Everyone Everywhere
by W. Kahan and J. D. Darcy (March 1998)

http://www.cs.berkeley.edu/~wkahan/JAVAhurt.pdf

The last page "Accuracy < Precision"

> From what I can see in your message, previous versions did not
deliberately find the minimum digit representation of floating point
number within the limit of ieee 754 standard.

-- 
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