From bug-request at octave dot org Sat Jan  7 21:04:22 2006
Subject: Re: etime in the new year
From: Bill Denney <denney at seas dot upenn dot edu>
To: Keith Goodman <kwgoodman at gmail dot com>
cc: stefan at sun dot ac dot za, bug@octave.org, jwe@bevo.che.wisc.edu
Date: Sat, 7 Jan 2006 22:03:11 -0500 (EST)

There is also a function is_leap_year in regular octave that implements 
this.  I actually was debating issuing a minor bug report on it that it's 
in the miscellaneous directory when it should be in the time directory.

Bill

On Sat, 7 Jan 2006, Keith Goodman wrote:

> On 1/7/06, Stefan van der Walt <stefan at sun dot ac dot za> wrote:
>> I saw formulas to calculate this thing in popular science magazines
>> before (Scientific American?).  I'm sure there must be a relatively
>> simple way to accomplish this?
>
> I can' t find it in Popular American (Scientific Science?). The first
> hit I found was from Microsoft (which is popular but not scientific
> and by recently censoring a Chinese blogger is...):
>
> "To determine if a year is a leap year, follow these steps:
> 1. If the year is evenly divisible by 4, go to step 2. Otherwise, go to step 5.
> 2. If the year is evenly divisible by 100, go to step 3. Otherwise, go
> to step 4.
> 3. If the year is evenly divisible by 400, go to step 4. Otherwise, go
> to step 5.
> 4. The year is a leap year (it has 366 days).
> 5. The year is not a leap year (it has 365 days)."
>
> The 1278th hit was from Octave:
>
>>> help is_leap_year
> is_leap_year is the user-defined function from the file
> /usr/local/share/octave/2.9.3/m/miscellaneous/is_leap_year.m
>
> -- Function File:  is_leap_year (YEAR)
>     Return 1 if the given year is a leap year and 0 otherwise.  If no
>     arguments are provided, `is_leap_year' will use the current year.
>     For example,
>
>          is_leap_year (2000)
>          => 1
>
> which uses the code
>
> retval = ((rem (year, 4) == 0 & rem (year, 100) != 0) ...
>            | rem (year, 400) == 0);
>
>
>
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-- 
"When I use a word," Humpty Dumpty said, in a rather scornful tone, "it
means just what I choose it to mean -- neither more nor less."
   -- Lewis Carroll



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