mk_cal_jpl

MkCalendar

Introduction

This is the gem library which calculates calendar datas, including old-calendar.(by JPL DE430)

Computable items

julian day(utc), julian day(jst), holiday, sekki_24, zassetsu,
yobi, kanshi, sekku, lambda(sun), alpha(moon), moonage,
old-calendar(year, month, day, leap flag), rokuyo

Original Text

旧暦計算サンプルプログラム
Copyright (C) 1993,1994 by H.Takano

Remark

However, the above program includes some problems for calculating the future
old-calendar datas. So, I have done some adjustments.(by JPL DE430 etc.)

Preparation

This library needs a JPL's DE430 binary file.

Download linux_p1550p2650.430 from ftp://ssd.jpl.nasa.gov/pub/eph/planets/Linux/de430/, and place at a suitable directory.

If neccessary, rename the binary file.

Installation

Add this line to your application's Gemfile:

gem 'mk_cal_jpl'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mk_cal_jpl

Usage

Instantiation

require 'mk_cal_jpl'

o = MkCalJpl.new("/path/to/<JPL DE430 binary>")

# Otherwise
o = MkCalJpl.new("/path/to/<JPL DE430 binary>", "20160916")

• Second argument should be JST(Format: %Y%m%d).
• If you don't set a second argument, this class considers the system time to have been set as a second argument(JST).

Calculation

year     = o.year
month    = o.month
day      = o.day
jd       = o.jd
jd_jst   = o.jd_jst
holiday  = o.holiday
sekki_24 = o.sekki_24
zassetsu = o.zassetsu
yobi     = o.yobi
kanshi   = o.kanshi
sekku    = o.sekku
lambda   = o.lambda
alpha    = o.alpha
moonage  = o.moonage
oc       = o.oc
str =  sprintf("%04d-%02d-%02d", year, month, day)
str << " #{yobi}曜日"
str << " #{holiday}" unless holiday == ""
str << " #{jd}UTC(#{jd_jst}JST) #{kanshi} "
str << sprintf("%04d-%02d-%02d", oc[0], oc[2], oc[3])
str << "(閏)" if oc[1] == 1
str << " #{oc[4]}"
str << " #{sekki_24}" unless sekki_24 == ""
str << " #{zassetsu}" unless zassetsu == ""
str << " #{sekku}" unless sekku == ""
str << " #{lambda} #{alpha} #{moonage}"
puts str

• It takes time for result output, because this library calculates correctly each time on loop processing.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment. Run bundle exec mk_cal_jpl to use the gem in this directory, ignoring other installed copies of this gem.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/komasaru/mk_cal_jpl.

License

The gem is available as open source under the terms of the MIT License.