public inbox for glibc-bugs@sourceware.org help / color / mirror / Atom feed
From: "zimmerma+gcc at loria dot fr" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug math/10716] New: various problems in cacosh and cacos Date: Thu, 01 Oct 2009 09:52:00 -0000 [thread overview] Message-ID: <20091001095223.10716.zimmerma+gcc@loria.fr> (raw) The classical branch cut for cacosh() is (-inf, 1). However, cacosh() is using a different branch cut. For example (courtesy of Kaveh Ghazi): cacosh(-1 + -0 I) -> (0 + 3.14159265358979 I) With the classical branch cut, one would get (0 - 3.14159265358979 I). Also the sign of 0 is not always correct: cacos(1 + 0 I) -> (0 + 0 I) [should be (0 - O I)] Finally the documentation of cacosh says that the real part of the result is chosen non-negative, which is clearly wrong on this example: cacosh(-3.45677995681763 + -2.3456699848175 I) -> (-2.11780021549476 + 2.53187508681341 I) See <http://lists.gforge.inria.fr/pipermail/mpc-discuss/2009-October/000581.html> for more details. -- Summary: various problems in cacosh and cacos Product: glibc Version: 2.10 Status: NEW Severity: normal Priority: P2 Component: math AssignedTo: aj at suse dot de ReportedBy: zimmerma+gcc at loria dot fr CC: glibc-bugs at sources dot redhat dot com GCC build triplet: x86_64-redhat-linux GCC host triplet: x86_64-redhat-linux GCC target triplet: x86_64-redhat-linux http://sourceware.org/bugzilla/show_bug.cgi?id=10716 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.
reply other threads:[~2009-10-01 9:52 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20091001095223.10716.zimmerma+gcc@loria.fr \ --to=sourceware-bugzilla@sourceware.org \ --cc=glibc-bugs@sources.redhat.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).