Date: Sun, 12 Aug 2012 23:12:38 -0000 From: Stephen Montgomery-Smith <stephen@missouri.edu> To: Peter Jeremy <peter@rulingia.com> Cc: Diane Bruce <db@db.net>, Bruce Evans <brde@optusnet.com.au>, John Baldwin <jhb@freebsd.org>, David Chisnall <theraven@freebsd.org>, Bruce Evans <bde@freebsd.org>, Steve Kargl <sgk@troutmask.apl.washington.edu>, David Schultz <das@freebsd.org>, Warner Losh <imp@bsdimp.com> Subject: Re: Use of C99 extra long double math functions after r236148 Message-ID: <500CA78E.2070302@missouri.edu> Resent-Message-ID: <20120812231231.GT20453@server.rulingia.com> In-Reply-To: <20120722231300.GA8033@server.rulingia.com> References: <20120721032448.X5744@besplex.bde.org> <5009BD6C.9050301@missouri.edu> <20120721123522.T877@besplex.bde.org> <500A2565.9090009@missouri.edu> <20120721181204.A1702@besplex.bde.org> <500B594D.1020305@missouri.edu> <20120722125300.P2246@besplex.bde.org> <500C1B1A.5070107@missouri.edu> <20120723015912.K5029@besplex.bde.org> <500C79A1.6080809@missouri.edu> <20120722231300.GA8033@server.rulingia.com>
next in thread | previous in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format. --------------030507040607030000090202 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit This is what I came up with for catanh. I seem to get a ULP less than 3. On 07/22/2012 06:13 PM, Peter Jeremy wrote: > The "normal" cases are (algorithmetically with '^' as exponentiation): > > catanh(z) = clog((1+z)/(1-z))/2 > = (clog(1+z) - clog(1-z))/2 > catanh(x+I*y) = log((y^2 + (1+x)^2)/(y^2 + (1-x)^2))/4 + I*atan2(y^2, 1-x^2-y^2)/2 > > None of these approaches behave cleanly when |z| is close to 1. If > you have some insights, feel free to work on it. > --------------030507040607030000090202--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?500CA78E.2070302>