On 6/29/07, James G. Sack (jim) <[EMAIL PROTECTED]> wrote:
Andrew Lentvorski wrote:
> Christopher Smith wrote:
>..
>> And of course his problem with "knowing" that a binary calculator
>> cannot represent 0.1 exactly, fails to recognize the capabilities of
>> calculators that maintain internal results as rational numbers
>
> None that I am aware of as still being in production do this.
Out of curiosity, how do the current crop of calculators deal with (eg)
"representing 0.1" exactly?
Do they use different representations in different ranges? (seems
unlikely to really work), or do they maybe recognize & distinguish
rationals?
The only calculators I have readily to hand are various vintages of
HP. As far as I can tell by some button pushing, they have no problem
with representing 0.1 exactly. I think that they are binary-coded
decimal and base 10 floating point internally. Somewhere I have a
book on programming the internal machine language of the HP 45, but I
am not looking for it right now.
It is the vast majority of digital computers that do not represent
decimal fractions such as 0.1 exactly. But this is a different part
of the problem space.
carl
--
carl lowenstein marine physical lab u.c. san diego
[EMAIL PROTECTED]
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