From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: Date: Mon, 29 Jun 2009 10:08:33 -0700 Message-ID: Subject: Re: [9fans] confusing astro output From: Russ Cox To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Topicbox-Message-UUID: 111914f2-ead5-11e9-9d60-3106f5b1d025 On Mon, Jun 15, 2009 at 11:33 AM, erik quanstrom wrote= : > i ran astro -k a 3 times, a few minutes apart > on the same machine. =C2=A0the results are suprising > > The sun sets at 20:47:50 EDT > The sun sets at 20:47:49 EDT > The sun sets at 20:47:43 EDT > > Comet rises at 23:02:57 EDT > Comet rises at 23:03:06 EDT > Comet rises at 23:03:02 EDT > > can anyone explain why i don't > get the same answer? from ken: astro "events" are found by a binary search (in time) on a "crossing" of the position of objects. for an event like "rise", "set", "twilight", the event is very vague because of atmospheric bending. in those cases, the binary search is stopped before the precision of the printing (1 sec). binary searches are started from the time that the command was executed. thus the time found for the crossing will vary.