From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <20111002163800.GA12773@polynum.com> References: <20111002163800.GA12773@polynum.com> Date: Mon, 3 Oct 2011 09:03:50 -0400 Message-ID: Subject: Re: [9fans] circular fonctions: precision? From: Russ Cox To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=UTF-8 Topicbox-Message-UUID: 2ffbcda4-ead7-11e9-9d60-3106f5b1d025 On Sun, Oct 2, 2011 at 12:38 PM, 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