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I'm not going to use GitHub Pages after all, because it is causing more problems than it is helping. All I really wanted was a way to host live JavaScript browser examples. I will find my own way of hosting just those. The main problem is that GitHub pages uses a different flavor of Markdown than GitHub. This makes it really difficult to get something that works right across both. In general, it doubles how much stuff I have to look at when I make a cosmetic change. So I have already turned off GitHub Pages on this repo, and this commit removes all links and references to it.
54 lines
2.2 KiB
JavaScript
54 lines
2.2 KiB
JavaScript
/*
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positions.js - by Don Cross - 2019-06-12
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Example Node.js program for Astronomy Engine:
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https://github.com/cosinekitty/astronomy
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This program calculates the equatorial and horizontal coordinates
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of the Sun, Moon, and planets, as seen by an observer at a specified
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location on the Earth.
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To execute, run the command:
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node positions.js latitude longitude [date]
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where
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latitude = geographic latitude of the observer (-90 to +90).
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longitude = geographic longitude of the observer (-180 to +180).
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date = optional date and time string.
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If date is omitted, this program uses the computer's current date and time.
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If date is present, date is any string that Node.js can parse as a date and time,
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for example the ISO 8601 UTC format "yyyy-mm-ddThh:mm:ssZ".
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*/
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const Astronomy = require('../../source/js/astronomy.js'); // adjust path as needed for your system
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function Format(x) {
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return x.toFixed(2).padStart(8);
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}
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function Demo() {
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if (process.argv.length === 4 || process.argv.length === 5) {
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const latitude = parseFloat(process.argv[2]);
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const longitude = parseFloat(process.argv[3]);
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const observer = Astronomy.MakeObserver(latitude, longitude, 0);
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const date = (process.argv.length === 5) ? new Date(process.argv[4]) : new Date();
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console.log(`UTC date = ${date.toISOString()}`);
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console.log('');
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console.log(`${'BODY'.padEnd(8)} ${'RA'.padStart(8)} ${'DEC'.padStart(8)} ${'AZ'.padStart(8)} ${'ALT'.padStart(8)}`);
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for (let body of ['Sun', 'Moon', 'Mercury', 'Venus', 'Mars', 'Jupiter', 'Saturn', 'Uranus', 'Neptune', 'Pluto']) {
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let equ_2000 = Astronomy.Equator(body, date, observer, false, true);
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let equ_ofdate = Astronomy.Equator(body, date, observer, true, true);
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let hor = Astronomy.Horizon(date, observer, equ_ofdate.ra, equ_ofdate.dec, 'normal');
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console.log(`${body.padEnd(8)} ${Format(equ_2000.ra)} ${Format(equ_2000.dec)} ${Format(hor.azimuth)} ${Format(hor.altitude)}`);
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}
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process.exit(0);
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}
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console.log('USAGE: node positions.js latitude longitude [date]');
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process.exit(1);
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}
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Demo();
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