Karim BELABAS on Tue, 25 Feb 2003 23:55:02 +0100 (MET)


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Re: zetakinit() puzzle


On Mon, 24 Feb 2003, Igor Schein wrote:
> Since we're talking about precision loss here, I'll mention a non-related
> case which I noticed some time ago:
>
> ? precision(sin(precision(2^2^7+.,38)))
> 9
>
> I can't judge whether it's a bug or not because I first need to understand
> something more basic ( see my message 2407 posted a few days ago).

Not a bug. I don't see how you can possibly reduce this mod 2Pi without
suffering catastrophic cancellation.

You actually escape a precision error by a narrow margin.

    Karim.
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Karim Belabas                    Tel: (+33) (0)1 69 15 57 48
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