Karim Belabas on Wed, 21 Nov 2018 18:18:55 +0100


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Re: Learning with GP: Taylor coefficients of xi(s) - Gram (Pari 2.12)


* Jacques Gélinas [2018-11-21 18:09]:
> { localprec(36); [
>   abs( 1 - zetah/zeta(1/2) ) < 2E-30,
>   ......................................................

I recommend 'exponent' for such tasks (fast check against some epsilon
whose exact value does not really matter), e.g.
    
    exponent(1 - zetah / zeta(1/2)) < -64

Cheers,

    K.B.

P.S. I also tend to favour localbitprec() over localprec() because it's
closer to the internal representation [ thus avoiding fiddling with
the likes of log(2) / log(10) ] ... and allows direct use of exponent().

--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite de Bordeaux         Fax: (+33) (0)5 40 00 21 23
351, cours de la Liberation    http://www.math.u-bordeaux.fr/~kbelabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux.fr/  [PARI/GP]
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