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From: Russ Cox <rsc@swtch.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] circular fonctions: precision?
Date: Mon,  3 Oct 2011 09:03:50 -0400	[thread overview]
Message-ID: <CADSkJJUgvPSSMLkw=XvShUxXextAkQkk5mHGU36mtc1x5y+zMA@mail.gmail.com> (raw)
In-Reply-To: <20111002163800.GA12773@polynum.com>

On Sun, Oct 2, 2011 at 12:38 PM,  <tlaronde@polynum.com> wrote:
> Is there some documentation about the precision of the circular (i.e
> trigonometric) fonctions, depending on the (plan9) implementation and
> the hardware?

They are not terribly accurate.

If you need accurate versions, the best I know are the ones
that were written at Sun and included in the FreeBSD math library.
There are copies on any FreeBSD machine and also in the
vx32 distribution: http://code.swtch.com/vx32/src/tip/src/libvxc/msun.

For Go, we started with implementations of the Plan 9 library
algorithms but have been slowly replacing them with implementations
of the Sun/FreeBSD algorithms for the improved accuracy.

Russ


  parent reply	other threads:[~2011-10-03 13:03 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-02 16:38 tlaronde
2011-10-02 17:52 ` Bakul Shah
2011-10-02 18:06   ` erik quanstrom
2011-10-02 18:40     ` Bakul Shah
2011-10-02 18:44       ` erik quanstrom
2011-10-02 18:59         ` andrew zerger
2011-10-02 19:04         ` tlaronde
2011-10-02 19:14         ` Bakul Shah
2011-10-02 19:18           ` erik quanstrom
2011-10-02 18:44     ` tlaronde
2011-10-02 18:48       ` tlaronde
2011-10-02 18:28   ` tlaronde
2011-10-02 19:06     ` Bakul Shah
2011-10-03 11:41       ` tlaronde
2011-10-03 14:39         ` Bakul Shah
2011-10-03 14:46           ` erik quanstrom
2011-10-03 15:29             ` Bakul Shah
2011-10-03 15:58               ` Bakul Shah
2011-10-03 16:49           ` tlaronde
2011-10-03 13:03 ` Russ Cox [this message]
2011-10-03 14:44   ` Bakul Shah
2011-10-03 14:57     ` Russ Cox
2011-10-03 15:34       ` Bakul Shah
2011-10-03 15:47         ` Russ Cox
2011-10-03 16:53   ` tlaronde

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