sergiolindau/computus

Calendar and astronomic calculations

Computus

Computus: Calendar and astronomical calculations.

Computus is a set of JavaScript modules (most of which have been written in TypeScript) that make calculations for the perpetual calendar with Easter and other moveable feast as well as astronomical calculations such as rise/noon/set times and positions for Sun, Moon and planets (ephemeris).

The code published in sergiolindau/Computus GitHub repository is hosted in computus.netlify.app for tests using Netlify hosting service.

Get a minified version from a CDN. To embed in a webpage using jsDelivr CDN copy the following HTML code:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/sergiolindau/Computus/computus.min.css" type="text/css" media="screen" charset="utf-8">
<script src='https://cdn.jsdelivr.net/gh/sergiolindau/Computus/computus.min.js'></script>

This project is a free software under the terms of MIT License.

Tests

• Perpetual Calendar (PerpetualCycle.html)
• Easter Sunday (EasterSunday.html)
• Computus static class source code (ComputusSource.html)
• Calendar (Calendar.html)
• Calendar Class Test
• Sun Calculator (Sun.html)
• LanguagePanel Test (LanguagePanel.html)
• GeoLocation Test (GeoLocation.html)
• GeoLocationPanel Test (GeoLocationPanel.html)
• Tick Test (Tick.html)
• DateTime Test (DateTime.html)
• DateTimePanel Test (DateTimePanel.html)
• Moon phases of the year (MoonYear.html))
• MarkedMathJaxWiki Test (MarkedMathJaxWiki.html)

Documentation

All documentation and additional information written for this project was made in Mardown files with embedded wiki like references, inline JavaScripts, inline and displayed Latex, source code highlights and graphics. To render them in HTML, an engine was developed combining the Marked, MathJax, highlight.js and Chart.js APIs. See the Repositories of APIs used.

The project documentation and some important information to carry out this project can be found here.

References

Calendar and Astronomy information

• SOFA - Standards of Fundamental Astronomy
• Paul Schlyter - How to compute planetary positions
• Paul Schlyter - Computing planetary positions - a tutorial with worked examples
• Paul Schlyter - How to compute rise/set times and altitude above horizon
• Paul Schlyter - Time Scales
• Approximate astronomical positions
• Eric Weisstein's World of Astronomy
• Homepage Dr A.R.Peters
• Don Cross - Solar System Calculator
• Don Cross - Dynamic Astronomy Calendar
• Don Cross - Astronomy Sky View
• The JPL Planetary and Lunar Ephemerides DE440 and DE441
• Jet Propulsion Laboratory - Solar System Dynamics
• NASA Eclipse website - Five Millennium Canon of Lunar Eclipses - Espenak and Meeus
• Astronomical Information Center on USA Navy
• Standish, E. M., Jr., Two Differing Definitions of the Dynamical Equinox and the Mean Obliquity, Astronomy and Astrophysics, Vol.101, P. L17, 1981.
• Wenceslao Segura González - Nuestro calendario. Una explicación científica, simple y completa
• Calendars through the Ages
• astro.vaporia.com - Astrophysics
• Påsktavla ur Liljegrens Runlära (ur Sverige Runinskrifter)
• Påsktavla ur Liljegrens Runlära (ur Sverige Runinskrifter) on Wikimedia
• ryanseys/lune and ironwallaby/lune on GitHub
• py-moon-phase on Launchpad
• Abbreviations of Months of the Year, Days of the Week, and Other Abbreviations of Time
• Standard Month and Days of the Week Abbreviations
• Astronomy & Astrophysics
• Samuel Vince, A Complete System of Astronomy, Volume 1, 1814
• Encyclopaedia Britannica - Astronomy
• Wikipedia - Astronomical system of units
• The IAU and astronomical units
• Hall, A., Elliptic Motion, Popular Astronomy, vol. 13, pp.287-296, 1905
• Astronomy Answers - Position of the Sun
• Science Direct - True Anomaly
• NASA Technical Translation, Edição 391

At NOAA ESRL

• NOAA ESRL: National Oceanic and Atmospheric Administration - Earth System Research Laboratories
• Sunrise/Sunset Calculator
• Solar Position Calculator

At Wikipedia

• Ciclo solar nos calendários
• Ciclo de Hiparco

Ephemeris

• Swiss Ephemeris - Astro.com
• mivion/swisseph
• mivion/ephemeris
• Astronomy and numerical software source codes - moshier.net
• xErik/ephemeris-moshier
• 0xStarcat/Moshier-Ephemeris-JS
• hemantgoswami/ephemeris
• clicktrend/ephemeris
• jgladch/npm-blastro
• Bill-Gray/jpl_eph
• chandantiwari/node-swisseph-api
• DoctorHowser/Ephemeris
• gmiller123456/jpl-development-ephemeris
• gmarty/vsop87
• rubyfmzk/Sirius
• david-rc-dayton/geohack
• stephaneworkspace/ephemeris_npm

Books

• Duffett-Smith, Peter, Practical Astronomy with your calculator, Cambridge University Press, 3rd edition 1988, ISBN 0-521-35699-7.
• Meeus, Jean, Astronomical Algorithms, Willmann-Bell, 1st English edition, 1991, ISBN 0-943396-35-2

Repositories of APIs used

In this section are the repositories of APIs used in this project

• MathJax
• Marked
• highlight.js
• Chart.js
• GoJS

Repositories of interest

• Modernizr
• DEVMEDIA: Apresentando a biblioteca JavaScript Modernizr
• x-marked
• ATNU/ng-computus
• rhnorskov/computus
• tohka/computus
• materiagris/computus
• algorithm-archive/contents/computus/computus.md
• Circiter/computus-in-sed

Javascript and API references

• ECMA-262: ECMAScript© language specification
• At developer.mozilla.org
  • Destructuring assignment
  • Strict mode
• Geolocation API @ W3C on GitHub
• Writing Mathematic Fomulars in Markdown
• Writing Mathematics for MathJax
• Top 5 : Best code syntax highlighter javascript plugins

Latex and Markdown references

• Markdown Guide
• Markdown Guide - Basic Syntax
• LaTeX2e unofficial reference manual
• ShareLatex Documentation
• Overleaf Documentation
• Latex quick reference
• Tables Generator

Locale and timezone data

• Wikipedia - Common Locale Data Repository
• Unicode CLDR Project
• unicode-org/cldr-json

License

MIT License

Copyright © 2017-2022 Sergio Lindau

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.