DateTime-Util-Astro

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LICENSE  view on Meta::CPAN

This is the license from "Calendrical Calculations", and code that was
ported from it.

---

The Functions (code, comments, and definitions) contained on this compact disk (the "Program") were written by Edward M. Reingold and Nachum Dershowitz (the "Authors"), who retain all rights to them except as granted in the License and subject to the...

The Authors' public service intent is more liberal than suggested by the License below, as are their licensing policies for otherwise nonallowed uses such as--without limitation--those in commercial, web-site, and large-scale academic contexts. Pleas...

http://www.calendarists.com

for all uses not authorized below; in case there is cause for doubt about whether a use you contemplate is authorized, please contact the Authors (email: reingold@iit.edu) . For commercial licensing information, contact the first author at the Depart...

1. LICENSE. The Authors grant you a license for personal use only. This means that for strictly personal use you may copy and use the code, and keep a backup or archival copy also. Any other uses, including without limitation, allowing the code or it...

2. WARRANTY.

(a) THE AUTHORS PROVIDE NO WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

(b) THE AUTHORS SHALL NOT BE LIABLE TO YOU OR ANY THIRD PARTIES FOR DAMAGES OF ANY KIND, INCLUDING WITHOUT LIMITATION, ANY LOST PROFITS, LOST SAVINGS, OR ANY OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR RELATED TO THE USE, INABILITY TO...

lib/DateTime/Util/Astro/Common.pm  view on Meta::CPAN

        angle(0, 0, 0.001813)
    );
}

# [1] p171 + errata 158
my %EC;
sub ephemeris_correction
{
    my $dt = shift;

    # we need a gregorian calendar, so make sure $dt is just 'DateTime'
    if (ref($dt) ne 'DateTime') {
        $dt = DateTime->from_object(object => $dt);
    }

    my $year = $dt->year;
    my $correction = $EC{ $year };
    if (! $correction) {
        if (1988 <= $year && $year <= 2019) {
            $correction = EC1($year - 1933);
        } elsif (1900 <= $year && $year <= 1987) {

lib/DateTime/Util/Astro/Common.pm  view on Meta::CPAN

    latitude  => $latitude,
    zone      => $zone,
    elevation => $elevation
  );

=head1 DESCRIPTION

DateTime::Util::Astro::Location implements some functions that are commonly
used for astronomical calculations. As with other DateTime::Util::Astro::
modules this module only implements the bare minimum required to make
astronomical calendars.

=head1 FUNCTIONS

=head2 aberration($dt)

Calculates the effect of the sun's moving during the time its light takes
takes to reach the Earth

=head2 dt_from_dynamical($moment)

lib/DateTime/Util/Astro/Moon.pm  view on Meta::CPAN

       qw(nth_new_moon lunar_phase lunar_longitude);

 my $dt        = nth_new_moon(24773); # should be 2003/12/23 UTC
 my $phase     = lunar_phase($dt);
 my $longitude = lunar_longitude($dt);

=head1 DESCRIPTION

This module provides functions to calculate lunar data, but its main
focus is to provide just enough functionality that allows us to
create lunisolar calendars and other DateTime related modules.

This module is a *straight* port from "Calendrical Calculations" [1] --
and therefore there are places where things can probably be "fixed" so
that they look more like Perl, as well as places where we could
leverage the DateTime functionalities better. If you see things that
doesn't quite look right (in Perl), that's probably because of that.

=head2 Notes On Accuracy

Before you use this module, please be aware that this module was originally
created B<solely> for the purpose of creating a lunisolar calendar for
the DateTime project (http://datetime.perl.org). 

We used [1] as basis for our calculations. While for most purposes the
results are accurate enough, you should note that the calculations from
this book are I<approximations>. 

Obviously we would like to make this module as good as possible, but
there's only so much you can do in the accuracy department. However, having
L<GMP|http://www.swox.com/gmp> and Math::BigInt::GMP may help a little bit.

lib/DateTime/Util/Astro/Sun.pm  view on Meta::CPAN

=head1 SYNOPSIS

  use DateTime::Util::Astro::Sun qw(solar_longitude);
  my $longitude = solar_longitude($dt);

=head1 DESCRIPTION

This module provides functions to calculate solar data, but its main
focus is to provide just enough functionality that allows us to
create lunisolar calendars and other DateTime related modules.

This module is a *straight* port from "Calendrical Calculations" [1] --
and therefore there are places where things can probably be "fixed" so
that they look more like Perl, as well as places where we could
leverage the DateTime functionalities better. If you see things that
doesn't quite look right (in Perl), that's probably because of that.

=head2 Notes On Accuracy

Before you use this module, please be aware that this module was originally
created B<solely> for the purpose of creating a lunisolar calendar for
the DateTime project (http://datetime.perl.org). 

We used [1] as basis for our calculations. While for most purposes the
results are accurate enough, you should note that the calculations from
this book are I<approximations>. 

Obviously we would like to make this module as good as possible, but
there's only so much you can do in the accuracy department. However, having
L<GMP|http://www.swox.com/gmp> and Math::BigInt::GMP may help a little bit.