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Ilya Zakharevich on Sat, 08 Dec 2018 04:23:00 +0100
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[BUG 2.11.1] Catastrophic loss of precision in intnum()
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- To: Developers Pari <pari-dev@list.cr.yp.to>
- Subject: [BUG 2.11.1] Catastrophic loss of precision in intnum()
- From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
- Date: Fri, 7 Dec 2018 19:00:35 -0800
- Delivery-date: Sat, 08 Dec 2018 04:23:00 +0100
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- User-agent: NeoMutt/20170113 (1.7.2)
(18:48) gp > intnum(X=0,2*Pi,sin(X)/(5+3*sin(X)))/Pi*6
time = 15 ms.
%1 = -0.99999999999999997197773738461849225609
Likewise with higher precision: half of the precision is lost.
(Do not know about when this first appeared… Could not find anything in the docs.)
Yours,
Ilya
P.S. Is there any way to communicate to intnum() that integration
happens over a period? This would require a drastically different
integration points…