mostaphaRoudsari/.block

## .block
license: mit

## README.md

      
    Raw
  

              README.md
            
          
    This is an example to use A-Frame and D3 together to create a scene, in this case a sunpath.
Next Steps

Add location drop down.
Add weather data overlay.
Add import epw to generate the sun path from an epw weather file.

Built with blockbuilder.org

  
## index.html
<head>
  <title>Sunpath using D3 and A-Frame</title>
  <script src="https://aframe.io/releases/1.0.4/aframe.min.js"></script>
  <script src="https://raw.githack.com/andreasplesch/aframe-meshline-component/master/dist/aframe-meshline-component.min.js"></script>
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="suncalc.js"></script>
</head>

<body>
  <a-scene>
    <a-entity id="line" meshline="lineWidth: 4; color: black"></a-entity>
		<a-entity id="analemma" meshline="lineWidth: 1; color: gray"></a-entity>
	<a-sky color="cyan"></a-sky>

  </a-scene>
</body>

<script>

	Date.prototype.stdTimezoneOffset = function() {
		var jan = new Date(this.getFullYear(), 0, 1);
		var jul = new Date(this.getFullYear(), 6, 1);
		return Math.max(jan.getTimezoneOffset(), jul.getTimezoneOffset());
	}

	Date.prototype.isDaylightSaving = function() {
		return this.getTimezoneOffset() < this.stdTimezoneOffset();
	}

  var radius = 10,
	lat = 39.95,
	lon = -75.16;

  // will be used later to color the suns
  var color = d3.scaleLinear()
    .range(["#3182bd", "#f33"]);

  // create the base plane
  var scene = d3.select("a-scene");

  scene.append('a-circle')
  	.attr("radius", radius)
  	.attr("position", "0 0 0")
  	.attr("rotation", "-90 0 0")
  	.attr("color", "gray");

	// draw daily sun curves
	for (var m = 0; m <= 11; m++){
		var points = [];
		for (var h = 0; h <= 24; h++){

			// add a point to curve for every 15 minutes to get a smoother curve
			for (var i=0; i <= 3; i++){
				var dt = new Date(2017, m, 21, h + i / 4);
				var p = getSunPositionXYZ(radius, dt, lat, lon);

				points.push(p.join(" "));

				// add sun sphere for each hour
				if (i == 0){
					scene.append('a-sphere')
						.attr("position", p.join(" "))
						.attr("radius", radius / 100)
						.attr("color", "yellow");
				}
			}
		}

		// append first point once more
		var dt = new Date(2017, 1, 21, 0);
		var p = getSunPositionXYZ(radius, dt, lat, lon);
		points.push(p.join(" "));

		// add a curve for each day
		scene.append('a-entity')
			.attr("meshline", "lineWidth: 2; path: " + points.join(","));
	}

	// get analemma positions
	for (var h = 0; h <= 24; h++){
		var points = [];
		var hour = h;
		for (var m = 0; m <= 12; m++){

			for (var d = 1; d <= 3; d++){

				var dt = new Date(2017, m, d * 7, hour);

				if ( dt.isDaylightSaving() ){
					dt = new Date(2017, m, d * 7, hour + 1);
				}

				var p = getSunPositionXYZ(radius, dt, lat, lon);

				points.push(p.join(" "));
			}
		}

		// add a curve for each hour
		scene.append('a-entity')
			.attr("meshline", "lineWidth: 2; path: " + points.join(","));
	}


	function getSunPositionXYZ( radius, time, latitude, longitude ) {
		/* from https://github.com/ladybug-tools/ladybug-web/blob/gh-pages/analemma-3d/analemma-3d-r18.html */
		var sunPosition, x, y, z;
		var d2r = Math.PI / 180;
		var r2d = 180 / Math.PI;

		sunPosition = SunCalc.getPosition( time, latitude, longitude);

		x = radius * Math.cos( sunPosition.altitude ) * Math.sin( sunPosition.azimuth + Math.PI );
		y = radius * Math.cos( sunPosition.altitude ) * Math.cos( sunPosition.azimuth + Math.PI );
		z = radius * Math.sin( sunPosition.altitude );

		return [x, z, y];
	}
</script>

## suncalc.js
/*
 (c) 2011-2015, Vladimir Agafonkin
 SunCalc is a JavaScript library for calculating sun/moon position and light phases.
 https://github.com/mourner/suncalc
*/

(function () { 'use strict';

// shortcuts for easier to read formulas

var PI   = Math.PI,
    sin  = Math.sin,
    cos  = Math.cos,
    tan  = Math.tan,
    asin = Math.asin,
    atan = Math.atan2,
    acos = Math.acos,
    rad  = PI / 180;

// sun calculations are based on http://aa.quae.nl/en/reken/zonpositie.html formulas


// date/time constants and conversions

var dayMs = 1000 * 60 * 60 * 24,
    J1970 = 2440588,
    J2000 = 2451545;

function toJulian(date) { return date.valueOf() / dayMs - 0.5 + J1970; }
function fromJulian(j)  { return new Date((j + 0.5 - J1970) * dayMs); }
function toDays(date)   { return toJulian(date) - J2000; }


// general calculations for position

var e = rad * 23.4397; // obliquity of the Earth

function rightAscension(l, b) { return atan(sin(l) * cos(e) - tan(b) * sin(e), cos(l)); }
function declination(l, b)    { return asin(sin(b) * cos(e) + cos(b) * sin(e) * sin(l)); }

function azimuth(H, phi, dec)  { return atan(sin(H), cos(H) * sin(phi) - tan(dec) * cos(phi)); }
function altitude(H, phi, dec) { return asin(sin(phi) * sin(dec) + cos(phi) * cos(dec) * cos(H)); }

function siderealTime(d, lw) { return rad * (280.16 + 360.9856235 * d) - lw; }

function astroRefraction(h) {
    if (h < 0) // the following formula works for positive altitudes only.
        h = 0; // if h = -0.08901179 a div/0 would occur.

    // formula 16.4 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
    // 1.02 / tan(h + 10.26 / (h + 5.10)) h in degrees, result in arc minutes -> converted to rad:
    return 0.0002967 / Math.tan(h + 0.00312536 / (h + 0.08901179));
}

// general sun calculations

function solarMeanAnomaly(d) { return rad * (357.5291 + 0.98560028 * d); }

function eclipticLongitude(M) {

    var C = rad * (1.9148 * sin(M) + 0.02 * sin(2 * M) + 0.0003 * sin(3 * M)), // equation of center
        P = rad * 102.9372; // perihelion of the Earth

    return M + C + P + PI;
}

function sunCoords(d) {

    var M = solarMeanAnomaly(d),
        L = eclipticLongitude(M);

    return {
        dec: declination(L, 0),
        ra: rightAscension(L, 0)
    };
}


var SunCalc = {};


// calculates sun position for a given date and latitude/longitude

SunCalc.getPosition = function (date, lat, lng) {

    var lw  = rad * -lng,
        phi = rad * lat,
        d   = toDays(date),

        c  = sunCoords(d),
        H  = siderealTime(d, lw) - c.ra;

    return {
        azimuth: azimuth(H, phi, c.dec),
        altitude: altitude(H, phi, c.dec)
    };
};


// sun times configuration (angle, morning name, evening name)

var times = SunCalc.times = [
    [-0.833, 'sunrise',       'sunset'      ],
    [  -0.3, 'sunriseEnd',    'sunsetStart' ],
    [    -6, 'dawn',          'dusk'        ],
    [   -12, 'nauticalDawn',  'nauticalDusk'],
    [   -18, 'nightEnd',      'night'       ],
    [     6, 'goldenHourEnd', 'goldenHour'  ]
];

// adds a custom time to the times config

SunCalc.addTime = function (angle, riseName, setName) {
    times.push([angle, riseName, setName]);
};


// calculations for sun times

var J0 = 0.0009;

function julianCycle(d, lw) { return Math.round(d - J0 - lw / (2 * PI)); }

function approxTransit(Ht, lw, n) { return J0 + (Ht + lw) / (2 * PI) + n; }
function solarTransitJ(ds, M, L)  { return J2000 + ds + 0.0053 * sin(M) - 0.0069 * sin(2 * L); }

function hourAngle(h, phi, d) { return acos((sin(h) - sin(phi) * sin(d)) / (cos(phi) * cos(d))); }

// returns set time for the given sun altitude
function getSetJ(h, lw, phi, dec, n, M, L) {

    var w = hourAngle(h, phi, dec),
        a = approxTransit(w, lw, n);
    return solarTransitJ(a, M, L);
}


// calculates sun times for a given date and latitude/longitude

SunCalc.getTimes = function (date, lat, lng) {

    var lw = rad * -lng,
        phi = rad * lat,

        d = toDays(date),
        n = julianCycle(d, lw),
        ds = approxTransit(0, lw, n),

        M = solarMeanAnomaly(ds),
        L = eclipticLongitude(M),
        dec = declination(L, 0),

        Jnoon = solarTransitJ(ds, M, L),

        i, len, time, Jset, Jrise;


    var result = {
        solarNoon: fromJulian(Jnoon),
        nadir: fromJulian(Jnoon - 0.5)
    };

    for (i = 0, len = times.length; i < len; i += 1) {
        time = times[i];

        Jset = getSetJ(time[0] * rad, lw, phi, dec, n, M, L);
        Jrise = Jnoon - (Jset - Jnoon);

        result[time[1]] = fromJulian(Jrise);
        result[time[2]] = fromJulian(Jset);
    }

    return result;
};


// moon calculations, based on http://aa.quae.nl/en/reken/hemelpositie.html formulas

function moonCoords(d) { // geocentric ecliptic coordinates of the moon

    var L = rad * (218.316 + 13.176396 * d), // ecliptic longitude
        M = rad * (134.963 + 13.064993 * d), // mean anomaly
        F = rad * (93.272 + 13.229350 * d),  // mean distance

        l  = L + rad * 6.289 * sin(M), // longitude
        b  = rad * 5.128 * sin(F),     // latitude
        dt = 385001 - 20905 * cos(M);  // distance to the moon in km

    return {
        ra: rightAscension(l, b),
        dec: declination(l, b),
        dist: dt
    };
}

SunCalc.getMoonPosition = function (date, lat, lng) {

    var lw  = rad * -lng,
        phi = rad * lat,
        d   = toDays(date),

        c = moonCoords(d),
        H = siderealTime(d, lw) - c.ra,
        h = altitude(H, phi, c.dec),
        // formula 14.1 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
        pa = atan(sin(H), tan(phi) * cos(c.dec) - sin(c.dec) * cos(H));

    h = h + astroRefraction(h); // altitude correction for refraction

    return {
        azimuth: azimuth(H, phi, c.dec),
        altitude: h,
        distance: c.dist,
        parallacticAngle: pa
    };
};


// calculations for illumination parameters of the moon,
// based on http://idlastro.gsfc.nasa.gov/ftp/pro/astro/mphase.pro formulas and
// Chapter 48 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.

SunCalc.getMoonIllumination = function (date) {

    var d = toDays(date),
        s = sunCoords(d),
        m = moonCoords(d),

        sdist = 149598000, // distance from Earth to Sun in km

        phi = acos(sin(s.dec) * sin(m.dec) + cos(s.dec) * cos(m.dec) * cos(s.ra - m.ra)),
        inc = atan(sdist * sin(phi), m.dist - sdist * cos(phi)),
        angle = atan(cos(s.dec) * sin(s.ra - m.ra), sin(s.dec) * cos(m.dec) -
                cos(s.dec) * sin(m.dec) * cos(s.ra - m.ra));

    return {
        fraction: (1 + cos(inc)) / 2,
        phase: 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI,
        angle: angle
    };
};


function hoursLater(date, h) {
    return new Date(date.valueOf() + h * dayMs / 24);
}

// calculations for moon rise/set times are based on http://www.stargazing.net/kepler/moonrise.html article

SunCalc.getMoonTimes = function (date, lat, lng, inUTC) {
    var t = new Date(date);
    if (inUTC) t.setUTCHours(0, 0, 0, 0);
    else t.setHours(0, 0, 0, 0);

    var hc = 0.133 * rad,
        h0 = SunCalc.getMoonPosition(t, lat, lng).altitude - hc,
        h1, h2, rise, set, a, b, xe, ye, d, roots, x1, x2, dx;

    // go in 2-hour chunks, each time seeing if a 3-point quadratic curve crosses zero (which means rise or set)
    for (var i = 1; i <= 24; i += 2) {
        h1 = SunCalc.getMoonPosition(hoursLater(t, i), lat, lng).altitude - hc;
        h2 = SunCalc.getMoonPosition(hoursLater(t, i + 1), lat, lng).altitude - hc;

        a = (h0 + h2) / 2 - h1;
        b = (h2 - h0) / 2;
        xe = -b / (2 * a);
        ye = (a * xe + b) * xe + h1;
        d = b * b - 4 * a * h1;
        roots = 0;

        if (d >= 0) {
            dx = Math.sqrt(d) / (Math.abs(a) * 2);
            x1 = xe - dx;
            x2 = xe + dx;
            if (Math.abs(x1) <= 1) roots++;
            if (Math.abs(x2) <= 1) roots++;
            if (x1 < -1) x1 = x2;
        }

        if (roots === 1) {
            if (h0 < 0) rise = i + x1;
            else set = i + x1;

        } else if (roots === 2) {
            rise = i + (ye < 0 ? x2 : x1);
            set = i + (ye < 0 ? x1 : x2);
        }

        if (rise && set) break;

        h0 = h2;
    }

    var result = {};

    if (rise) result.rise = hoursLater(t, rise);
    if (set) result.set = hoursLater(t, set);

    if (!rise && !set) result[ye > 0 ? 'alwaysUp' : 'alwaysDown'] = true;

    return result;
};


// export as AMD module / Node module / browser variable
if (typeof define === 'function' && define.amd) define(SunCalc);
else if (typeof module !== 'undefined') module.exports = SunCalc;
else window.SunCalc = SunCalc;

}());

## thumbnail.png

      
    Raw
  

              thumbnail.png
	<head>
	<title>Sunpath using D3 and A-Frame</title>
	<script src="https://aframe.io/releases/1.0.4/aframe.min.js"></script>
	<script src="https://raw.githack.com/andreasplesch/aframe-meshline-component/master/dist/aframe-meshline-component.min.js"></script>
	<script src="https://d3js.org/d3.v4.min.js"></script>
	<script src="suncalc.js"></script>
	</head>

	<body>
	<a-scene>
	<a-entity id="line" meshline="lineWidth: 4; color: black"></a-entity>
	<a-entity id="analemma" meshline="lineWidth: 1; color: gray"></a-entity>
	<a-sky color="cyan"></a-sky>

	</a-scene>
	</body>

	<script>

	Date.prototype.stdTimezoneOffset = function() {
	var jan = new Date(this.getFullYear(), 0, 1);
	var jul = new Date(this.getFullYear(), 6, 1);
	return Math.max(jan.getTimezoneOffset(), jul.getTimezoneOffset());
	}

	Date.prototype.isDaylightSaving = function() {
	return this.getTimezoneOffset() < this.stdTimezoneOffset();
	}

	var radius = 10,
	lat = 39.95,
	lon = -75.16;

	// will be used later to color the suns
	var color = d3.scaleLinear()
	.range(["#3182bd", "#f33"]);

	// create the base plane
	var scene = d3.select("a-scene");

	scene.append('a-circle')
	.attr("radius", radius)
	.attr("position", "0 0 0")
	.attr("rotation", "-90 0 0")
	.attr("color", "gray");

	// draw daily sun curves
	for (var m = 0; m <= 11; m++){
	var points = [];
	for (var h = 0; h <= 24; h++){

	// add a point to curve for every 15 minutes to get a smoother curve
	for (var i=0; i <= 3; i++){
	var dt = new Date(2017, m, 21, h + i / 4);
	var p = getSunPositionXYZ(radius, dt, lat, lon);

	points.push(p.join(" "));

	// add sun sphere for each hour
	if (i == 0){
	scene.append('a-sphere')
	.attr("position", p.join(" "))
	.attr("radius", radius / 100)
	.attr("color", "yellow");
	}
	}
	}

	// append first point once more
	var dt = new Date(2017, 1, 21, 0);
	var p = getSunPositionXYZ(radius, dt, lat, lon);
	points.push(p.join(" "));

	// add a curve for each day
	scene.append('a-entity')
	.attr("meshline", "lineWidth: 2; path: " + points.join(","));
	}

	// get analemma positions
	for (var h = 0; h <= 24; h++){
	var points = [];
	var hour = h;
	for (var m = 0; m <= 12; m++){

	for (var d = 1; d <= 3; d++){

	var dt = new Date(2017, m, d * 7, hour);

	if ( dt.isDaylightSaving() ){
	dt = new Date(2017, m, d * 7, hour + 1);
	}

	var p = getSunPositionXYZ(radius, dt, lat, lon);

	points.push(p.join(" "));
	}
	}

	// add a curve for each hour
	scene.append('a-entity')
	.attr("meshline", "lineWidth: 2; path: " + points.join(","));
	}


	function getSunPositionXYZ( radius, time, latitude, longitude ) {
	/* from https://github.com/ladybug-tools/ladybug-web/blob/gh-pages/analemma-3d/analemma-3d-r18.html */
	var sunPosition, x, y, z;
	var d2r = Math.PI / 180;
	var r2d = 180 / Math.PI;

	sunPosition = SunCalc.getPosition( time, latitude, longitude);

	x = radius * Math.cos( sunPosition.altitude ) * Math.sin( sunPosition.azimuth + Math.PI );
	y = radius * Math.cos( sunPosition.altitude ) * Math.cos( sunPosition.azimuth + Math.PI );
	z = radius * Math.sin( sunPosition.altitude );

	return [x, z, y];
	}
	</script>
	/*
	(c) 2011-2015, Vladimir Agafonkin
	SunCalc is a JavaScript library for calculating sun/moon position and light phases.
	https://github.com/mourner/suncalc
	*/

	(function () { 'use strict';

	// shortcuts for easier to read formulas

	var PI = Math.PI,
	sin = Math.sin,
	cos = Math.cos,
	tan = Math.tan,
	asin = Math.asin,
	atan = Math.atan2,
	acos = Math.acos,
	rad = PI / 180;

	// sun calculations are based on http://aa.quae.nl/en/reken/zonpositie.html formulas


	// date/time constants and conversions

	var dayMs = 1000 * 60 * 60 * 24,
	J1970 = 2440588,
	J2000 = 2451545;

	function toJulian(date) { return date.valueOf() / dayMs - 0.5 + J1970; }
	function fromJulian(j) { return new Date((j + 0.5 - J1970) * dayMs); }
	function toDays(date) { return toJulian(date) - J2000; }


	// general calculations for position

	var e = rad * 23.4397; // obliquity of the Earth

	function rightAscension(l, b) { return atan(sin(l) * cos(e) - tan(b) * sin(e), cos(l)); }
	function declination(l, b) { return asin(sin(b) * cos(e) + cos(b) * sin(e) * sin(l)); }

	function azimuth(H, phi, dec) { return atan(sin(H), cos(H) * sin(phi) - tan(dec) * cos(phi)); }
	function altitude(H, phi, dec) { return asin(sin(phi) * sin(dec) + cos(phi) * cos(dec) * cos(H)); }

	function siderealTime(d, lw) { return rad * (280.16 + 360.9856235 * d) - lw; }

	function astroRefraction(h) {
	if (h < 0) // the following formula works for positive altitudes only.
	h = 0; // if h = -0.08901179 a div/0 would occur.

	// formula 16.4 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
	// 1.02 / tan(h + 10.26 / (h + 5.10)) h in degrees, result in arc minutes -> converted to rad:
	return 0.0002967 / Math.tan(h + 0.00312536 / (h + 0.08901179));
	}

	// general sun calculations

	function solarMeanAnomaly(d) { return rad * (357.5291 + 0.98560028 * d); }

	function eclipticLongitude(M) {

	var C = rad * (1.9148 * sin(M) + 0.02 * sin(2 * M) + 0.0003 * sin(3 * M)), // equation of center
	P = rad * 102.9372; // perihelion of the Earth

	return M + C + P + PI;
	}

	function sunCoords(d) {

	var M = solarMeanAnomaly(d),
	L = eclipticLongitude(M);

	return {
	dec: declination(L, 0),
	ra: rightAscension(L, 0)
	};
	}


	var SunCalc = {};


	// calculates sun position for a given date and latitude/longitude

	SunCalc.getPosition = function (date, lat, lng) {

	var lw = rad * -lng,
	phi = rad * lat,
	d = toDays(date),

	c = sunCoords(d),
	H = siderealTime(d, lw) - c.ra;

	return {
	azimuth: azimuth(H, phi, c.dec),
	altitude: altitude(H, phi, c.dec)
	};
	};


	// sun times configuration (angle, morning name, evening name)

	var times = SunCalc.times = [
	[-0.833, 'sunrise', 'sunset' ],
	[ -0.3, 'sunriseEnd', 'sunsetStart' ],
	[ -6, 'dawn', 'dusk' ],
	[ -12, 'nauticalDawn', 'nauticalDusk'],
	[ -18, 'nightEnd', 'night' ],
	[ 6, 'goldenHourEnd', 'goldenHour' ]
	];

	// adds a custom time to the times config

	SunCalc.addTime = function (angle, riseName, setName) {
	times.push([angle, riseName, setName]);
	};


	// calculations for sun times

	var J0 = 0.0009;

	function julianCycle(d, lw) { return Math.round(d - J0 - lw / (2 * PI)); }

	function approxTransit(Ht, lw, n) { return J0 + (Ht + lw) / (2 * PI) + n; }
	function solarTransitJ(ds, M, L) { return J2000 + ds + 0.0053 * sin(M) - 0.0069 * sin(2 * L); }

	function hourAngle(h, phi, d) { return acos((sin(h) - sin(phi) * sin(d)) / (cos(phi) * cos(d))); }

	// returns set time for the given sun altitude
	function getSetJ(h, lw, phi, dec, n, M, L) {

	var w = hourAngle(h, phi, dec),
	a = approxTransit(w, lw, n);
	return solarTransitJ(a, M, L);
	}


	// calculates sun times for a given date and latitude/longitude

	SunCalc.getTimes = function (date, lat, lng) {

	var lw = rad * -lng,
	phi = rad * lat,

	d = toDays(date),
	n = julianCycle(d, lw),
	ds = approxTransit(0, lw, n),

	M = solarMeanAnomaly(ds),
	L = eclipticLongitude(M),
	dec = declination(L, 0),

	Jnoon = solarTransitJ(ds, M, L),

	i, len, time, Jset, Jrise;


	var result = {
	solarNoon: fromJulian(Jnoon),
	nadir: fromJulian(Jnoon - 0.5)
	};

	for (i = 0, len = times.length; i < len; i += 1) {
	time = times[i];

	Jset = getSetJ(time[0] * rad, lw, phi, dec, n, M, L);
	Jrise = Jnoon - (Jset - Jnoon);

	result[time[1]] = fromJulian(Jrise);
	result[time[2]] = fromJulian(Jset);
	}

	return result;
	};


	// moon calculations, based on http://aa.quae.nl/en/reken/hemelpositie.html formulas

	function moonCoords(d) { // geocentric ecliptic coordinates of the moon

	var L = rad * (218.316 + 13.176396 * d), // ecliptic longitude
	M = rad * (134.963 + 13.064993 * d), // mean anomaly
	F = rad * (93.272 + 13.229350 * d), // mean distance

	l = L + rad * 6.289 * sin(M), // longitude
	b = rad * 5.128 * sin(F), // latitude
	dt = 385001 - 20905 * cos(M); // distance to the moon in km

	return {
	ra: rightAscension(l, b),
	dec: declination(l, b),
	dist: dt
	};
	}

	SunCalc.getMoonPosition = function (date, lat, lng) {

	var lw = rad * -lng,
	phi = rad * lat,
	d = toDays(date),

	c = moonCoords(d),
	H = siderealTime(d, lw) - c.ra,
	h = altitude(H, phi, c.dec),
	// formula 14.1 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
	pa = atan(sin(H), tan(phi) * cos(c.dec) - sin(c.dec) * cos(H));

	h = h + astroRefraction(h); // altitude correction for refraction

	return {
	azimuth: azimuth(H, phi, c.dec),
	altitude: h,
	distance: c.dist,
	parallacticAngle: pa
	};
	};


	// calculations for illumination parameters of the moon,
	// based on http://idlastro.gsfc.nasa.gov/ftp/pro/astro/mphase.pro formulas and
	// Chapter 48 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.

	SunCalc.getMoonIllumination = function (date) {

	var d = toDays(date),
	s = sunCoords(d),
	m = moonCoords(d),

	sdist = 149598000, // distance from Earth to Sun in km

	phi = acos(sin(s.dec) * sin(m.dec) + cos(s.dec) * cos(m.dec) * cos(s.ra - m.ra)),
	inc = atan(sdist * sin(phi), m.dist - sdist * cos(phi)),
	angle = atan(cos(s.dec) * sin(s.ra - m.ra), sin(s.dec) * cos(m.dec) -
	cos(s.dec) * sin(m.dec) * cos(s.ra - m.ra));

	return {
	fraction: (1 + cos(inc)) / 2,
	phase: 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI,
	angle: angle
	};
	};


	function hoursLater(date, h) {
	return new Date(date.valueOf() + h * dayMs / 24);
	}

	// calculations for moon rise/set times are based on http://www.stargazing.net/kepler/moonrise.html article

	SunCalc.getMoonTimes = function (date, lat, lng, inUTC) {
	var t = new Date(date);
	if (inUTC) t.setUTCHours(0, 0, 0, 0);
	else t.setHours(0, 0, 0, 0);

	var hc = 0.133 * rad,
	h0 = SunCalc.getMoonPosition(t, lat, lng).altitude - hc,
	h1, h2, rise, set, a, b, xe, ye, d, roots, x1, x2, dx;

	// go in 2-hour chunks, each time seeing if a 3-point quadratic curve crosses zero (which means rise or set)
	for (var i = 1; i <= 24; i += 2) {
	h1 = SunCalc.getMoonPosition(hoursLater(t, i), lat, lng).altitude - hc;
	h2 = SunCalc.getMoonPosition(hoursLater(t, i + 1), lat, lng).altitude - hc;

	a = (h0 + h2) / 2 - h1;
	b = (h2 - h0) / 2;
	xe = -b / (2 * a);
	ye = (a * xe + b) * xe + h1;
	d = b * b - 4 * a * h1;
	roots = 0;

	if (d >= 0) {
	dx = Math.sqrt(d) / (Math.abs(a) * 2);
	x1 = xe - dx;
	x2 = xe + dx;
	if (Math.abs(x1) <= 1) roots++;
	if (Math.abs(x2) <= 1) roots++;
	if (x1 < -1) x1 = x2;
	}

	if (roots === 1) {
	if (h0 < 0) rise = i + x1;
	else set = i + x1;

	} else if (roots === 2) {
	rise = i + (ye < 0 ? x2 : x1);
	set = i + (ye < 0 ? x1 : x2);
	}

	if (rise && set) break;

	h0 = h2;
	}

	var result = {};

	if (rise) result.rise = hoursLater(t, rise);
	if (set) result.set = hoursLater(t, set);

	if (!rise && !set) result[ye > 0 ? 'alwaysUp' : 'alwaysDown'] = true;

	return result;
	};


	// export as AMD module / Node module / browser variable
	if (typeof define === 'function' && define.amd) define(SunCalc);
	else if (typeof module !== 'undefined') module.exports = SunCalc;
	else window.SunCalc = SunCalc;

	}());