[Discuss] Financial database / balance?

[gaf at blu.org (Jerry Feldman)]

On 01/15/2012 02:51 PM, Richard Pieri wrote:
> On Jan 15, 2012, at 1:56 PM, markw at mohawksoft.com wrote:
>> You are confusing "display" of a double with "use" of a double.
>> 0.36999999999999999556 is numerically, with finite precision less than 15
>> decimal places, effectively 0.37.
> No, I'm not.  While .369999999 etc. is "effectively" 0.37, it isn't 0.37.  Do an amortization of your IRA with doubles and with arbitrary precision BCD.  You'll get different results, and the doubles math result will be wrong.
>
> Wrong is not good enough for anyone's finances.
>
While Mark is correct based on display and rounding the number 0.37
cannot be implemented exactly in a binary floating point number. There
is always that error, as Richard points out.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
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