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prayertime-fr.js
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prayertime-fr.js
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/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Latitude/longitude spherical geodesy formulae & scripts (c) Chris Veness 2002-2015
- www.movable-type.co.uk/scripts/latlong.html MIT @license
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
'use strict';
// if (typeof module!='undefined' && module.exports) var Dms = require('./dms'); // CommonJS (Node)
/**
* Creates a LatLon point on the earth's surface at the specified latitude / longitude.
*
* @classdesc Tools for geodetic calculations
* @requires Dms from 'dms.js'
*
* @constructor
* @param {number} lat - Latitude in degrees.
* @param {number} lon - Longitude in degrees.
*
* @example
* var p1 = new LatLon(52.205, 0.119);
*/
function LatLon(lat, lon) {
// allow instantiation without 'new'
if (!(this instanceof LatLon)) return new LatLon(lat, lon);
this.lat = Number(lat);
this.lon = Number(lon);
}
/**
* Returns the distance from 'this' point to destination point (using haversine formula).
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @param {number} [radius=6371e3] - (Mean) radius of earth (defaults to radius in metres).
* @returns {number} Distance between this point and destination point, in same units as radius.
*
* @example
* var p1 = new LatLon(52.205, 0.119), p2 = new LatLon(48.857, 2.351);
* var d = p1.distanceTo(p2); // Number(d.toPrecision(4)): 404300
*/
LatLon.prototype.distanceTo = function(point, radius) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
radius = (radius === undefined) ? 6371e3 : Number(radius);
var R = radius;
var φ1 = this.lat.toRadians(), λ1 = this.lon.toRadians();
var φ2 = point.lat.toRadians(), λ2 = point.lon.toRadians();
var Δφ = φ2 - φ1;
var Δλ = λ2 - λ1;
var a = Math.sin(Δφ/2) * Math.sin(Δφ/2) +
Math.cos(φ1) * Math.cos(φ2) *
Math.sin(Δλ/2) * Math.sin(Δλ/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
return d;
};
/**
* Returns the (initial) bearing from 'this' point to destination point.
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @returns {number} Initial bearing in degrees from north.
*
* @example
* var p1 = new LatLon(52.205, 0.119), p2 = new LatLon(48.857, 2.351);
* var b1 = p1.bearingTo(p2); // b1.toFixed(1): 156.2
*/
LatLon.prototype.bearingTo = function(point) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
var φ1 = this.lat.toRadians(), φ2 = point.lat.toRadians();
var Δλ = (point.lon-this.lon).toRadians();
// see http://mathforum.org/library/drmath/view/55417.html
var y = Math.sin(Δλ) * Math.cos(φ2);
var x = Math.cos(φ1)*Math.sin(φ2) -
Math.sin(φ1)*Math.cos(φ2)*Math.cos(Δλ);
var θ = Math.atan2(y, x);
return (θ.toDegrees()+360) % 360;
};
/**
* Returns final bearing arriving at destination destination point from 'this' point; the final bearing
* will differ from the initial bearing by varying degrees according to distance and latitude.
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @returns {number} Final bearing in degrees from north.
*
* @example
* var p1 = new LatLon(52.205, 0.119), p2 = new LatLon(48.857, 2.351);
* var b2 = p1.finalBearingTo(p2); // b2.toFixed(1): 157.9
*/
LatLon.prototype.finalBearingTo = function(point) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
// get initial bearing from destination point to this point & reverse it by adding 180°
return ( point.bearingTo(this)+180 ) % 360;
};
/**
* Returns the midpoint between 'this' point and the supplied point.
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @returns {LatLon} Midpoint between this point and the supplied point.
*
* @example
* var p1 = new LatLon(52.205, 0.119), p2 = new LatLon(48.857, 2.351);
* var pMid = p1.midpointTo(p2); // pMid.toString(): 50.5363°N, 001.2746°E
*/
LatLon.prototype.midpointTo = function(point) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
// see http://mathforum.org/library/drmath/view/51822.html for derivation
var φ1 = this.lat.toRadians(), λ1 = this.lon.toRadians();
var φ2 = point.lat.toRadians();
var Δλ = (point.lon-this.lon).toRadians();
var Bx = Math.cos(φ2) * Math.cos(Δλ);
var By = Math.cos(φ2) * Math.sin(Δλ);
var φ3 = Math.atan2(Math.sin(φ1)+Math.sin(φ2),
Math.sqrt( (Math.cos(φ1)+Bx)*(Math.cos(φ1)+Bx) + By*By) );
var λ3 = λ1 + Math.atan2(By, Math.cos(φ1) + Bx);
λ3 = (λ3+3*Math.PI) % (2*Math.PI) - Math.PI; // normalise to -180..+180°
return new LatLon(φ3.toDegrees(), λ3.toDegrees());
};
/**
* Returns the destination point from 'this' point having travelled the given distance on the
* given initial bearing (bearing normally varies around path followed).
*
* @param {number} distance - Distance travelled, in same units as earth radius (default: metres).
* @param {number} bearing - Initial bearing in degrees from north.
* @param {number} [radius=6371e3] - (Mean) radius of earth (defaults to radius in metres).
* @returns {LatLon} Destination point.
*
* @example
* var p1 = new LatLon(51.4778, -0.0015);
* var p2 = p1.destinationPoint(7794, 300.7); // p2.toString(): 51.5135°N, 000.0983°W
*/
LatLon.prototype.destinationPoint = function(distance, bearing, radius) {
radius = (radius === undefined) ? 6371e3 : Number(radius);
// see http://williams.best.vwh.net/avform.htm#LL
var δ = Number(distance) / radius; // angular distance in radians
var θ = Number(bearing).toRadians();
var φ1 = this.lat.toRadians();
var λ1 = this.lon.toRadians();
var φ2 = Math.asin( Math.sin(φ1)*Math.cos(δ) +
Math.cos(φ1)*Math.sin(δ)*Math.cos(θ) );
var λ2 = λ1 + Math.atan2(Math.sin(θ)*Math.sin(δ)*Math.cos(φ1),
Math.cos(δ)-Math.sin(φ1)*Math.sin(φ2));
λ2 = (λ2+3*Math.PI) % (2*Math.PI) - Math.PI; // normalise to -180..+180°
return new LatLon(φ2.toDegrees(), λ2.toDegrees());
};
/**
* Returns the point of intersection of two paths defined by point and bearing.
*
* @param {LatLon} p1 - First point.
* @param {number} brng1 - Initial bearing from first point.
* @param {LatLon} p2 - Second point.
* @param {number} brng2 - Initial bearing from second point.
* @returns {LatLon} Destination point (null if no unique intersection defined).
*
* @example
* var p1 = LatLon(51.8853, 0.2545), brng1 = 108.547;
* var p2 = LatLon(49.0034, 2.5735), brng2 = 32.435;
* var pInt = LatLon.intersection(p1, brng1, p2, brng2); // pInt.toString(): 50.9078°N, 004.5084°E
*/
LatLon.intersection = function(p1, brng1, p2, brng2) {
if (!(p1 instanceof LatLon)) throw new TypeError('p1 is not LatLon object');
if (!(p2 instanceof LatLon)) throw new TypeError('p2 is not LatLon object');
// see http://williams.best.vwh.net/avform.htm#Intersection
var φ1 = p1.lat.toRadians(), λ1 = p1.lon.toRadians();
var φ2 = p2.lat.toRadians(), λ2 = p2.lon.toRadians();
var θ13 = Number(brng1).toRadians(), θ23 = Number(brng2).toRadians();
var Δφ = φ2-φ1, Δλ = λ2-λ1;
var δ12 = 2*Math.asin( Math.sqrt( Math.sin(Δφ/2)*Math.sin(Δφ/2) +
Math.cos(φ1)*Math.cos(φ2)*Math.sin(Δλ/2)*Math.sin(Δλ/2) ) );
if (δ12 == 0) return null;
// initial/final bearings between points
var θ1 = Math.acos( ( Math.sin(φ2) - Math.sin(φ1)*Math.cos(δ12) ) /
( Math.sin(δ12)*Math.cos(φ1) ) );
if (isNaN(θ1)) θ1 = 0; // protect against rounding
var θ2 = Math.acos( ( Math.sin(φ1) - Math.sin(φ2)*Math.cos(δ12) ) /
( Math.sin(δ12)*Math.cos(φ2) ) );
var θ12, θ21;
if (Math.sin(λ2-λ1) > 0) {
θ12 = θ1;
θ21 = 2*Math.PI - θ2;
} else {
θ12 = 2*Math.PI - θ1;
θ21 = θ2;
}
var α1 = (θ13 - θ12 + Math.PI) % (2*Math.PI) - Math.PI; // angle 2-1-3
var α2 = (θ21 - θ23 + Math.PI) % (2*Math.PI) - Math.PI; // angle 1-2-3
if (Math.sin(α1)==0 && Math.sin(α2)==0) return null; // infinite intersections
if (Math.sin(α1)*Math.sin(α2) < 0) return null; // ambiguous intersection
//α1 = Math.abs(α1);
//α2 = Math.abs(α2);
// ... Ed Williams takes abs of α1/α2, but seems to break calculation?
var α3 = Math.acos( -Math.cos(α1)*Math.cos(α2) +
Math.sin(α1)*Math.sin(α2)*Math.cos(δ12) );
var δ13 = Math.atan2( Math.sin(δ12)*Math.sin(α1)*Math.sin(α2),
Math.cos(α2)+Math.cos(α1)*Math.cos(α3) );
var φ3 = Math.asin( Math.sin(φ1)*Math.cos(δ13) +
Math.cos(φ1)*Math.sin(δ13)*Math.cos(θ13) );
var Δλ13 = Math.atan2( Math.sin(θ13)*Math.sin(δ13)*Math.cos(φ1),
Math.cos(δ13)-Math.sin(φ1)*Math.sin(φ3) );
var λ3 = λ1 + Δλ13;
λ3 = (λ3+3*Math.PI) % (2*Math.PI) - Math.PI; // normalise to -180..+180°
return new LatLon(φ3.toDegrees(), λ3.toDegrees());
};
/**
* Returns (signed) distance from ‘this’ point to great circle defined by start-point and end-point.
*
* @param {LatLon} pathStart - Start point of great circle path.
* @param {LatLon} pathEnd - End point of great circle path.
* @param {number} [radius=6371e3] - (Mean) radius of earth (defaults to radius in metres).
* @returns {number} Distance to great circle (-ve if to left, +ve if to right of path).
*
* @example
* var pCurrent = new LatLon(53.2611, -0.7972);
* var p1 = new LatLon(53.3206, -1.7297), p2 = new LatLon(53.1887, 0.1334);
* var d = pCurrent.crossTrackDistanceTo(p1, p2); // Number(d.toPrecision(4)): -307.5
*/
LatLon.prototype.crossTrackDistanceTo = function(pathStart, pathEnd, radius) {
if (!(pathStart instanceof LatLon)) throw new TypeError('pathStart is not LatLon object');
if (!(pathEnd instanceof LatLon)) throw new TypeError('pathEnd is not LatLon object');
radius = (radius === undefined) ? 6371e3 : Number(radius);
var δ13 = pathStart.distanceTo(this, radius)/radius;
var θ13 = pathStart.bearingTo(this).toRadians();
var θ12 = pathStart.bearingTo(pathEnd).toRadians();
var dxt = Math.asin( Math.sin(δ13) * Math.sin(θ13-θ12) ) * radius;
return dxt;
};
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/**
* Returns the distance travelling from 'this' point to destination point along a rhumb line.
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @param {number} [radius=6371e3] - (Mean) radius of earth (defaults to radius in metres).
* @returns {number} Distance in km between this point and destination point (same units as radius).
*
* @example
* var p1 = new LatLon(51.127, 1.338), p2 = new LatLon(50.964, 1.853);
* var d = p1.distanceTo(p2); // Number(d.toPrecision(4)): 40310
*/
LatLon.prototype.rhumbDistanceTo = function(point, radius) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
radius = (radius === undefined) ? 6371e3 : Number(radius);
// see http://williams.best.vwh.net/avform.htm#Rhumb
var R = radius;
var φ1 = this.lat.toRadians(), φ2 = point.lat.toRadians();
var Δφ = φ2 - φ1;
var Δλ = Math.abs(point.lon-this.lon).toRadians();
// if dLon over 180° take shorter rhumb line across the anti-meridian:
if (Math.abs(Δλ) > Math.PI) Δλ = Δλ>0 ? -(2*Math.PI-Δλ) : (2*Math.PI+Δλ);
// on Mercator projection, longitude distances shrink by latitude; q is the 'stretch factor'
// q becomes ill-conditioned along E-W line (0/0); use empirical tolerance to avoid it
var Δψ = Math.log(Math.tan(φ2/2+Math.PI/4)/Math.tan(φ1/2+Math.PI/4));
var q = Math.abs(Δψ) > 10e-12 ? Δφ/Δψ : Math.cos(φ1);
// distance is pythagoras on 'stretched' Mercator projection
var δ = Math.sqrt(Δφ*Δφ + q*q*Δλ*Δλ); // angular distance in radians
var dist = δ * R;
return dist;
};
/**
* Returns the bearing from 'this' point to destination point along a rhumb line.
*
* @param {LatLon} point - Latitude/longitude of destination point.
* @returns {number} Bearing in degrees from north.
*
* @example
* var p1 = new LatLon(51.127, 1.338), p2 = new LatLon(50.964, 1.853);
* var d = p1.rhumbBearingTo(p2); // d.toFixed(1): 116.7
*/
LatLon.prototype.rhumbBearingTo = function(point) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
var φ1 = this.lat.toRadians(), φ2 = point.lat.toRadians();
var Δλ = (point.lon-this.lon).toRadians();
// if dLon over 180° take shorter rhumb line across the anti-meridian:
if (Math.abs(Δλ) > Math.PI) Δλ = Δλ>0 ? -(2*Math.PI-Δλ) : (2*Math.PI+Δλ);
var Δψ = Math.log(Math.tan(φ2/2+Math.PI/4)/Math.tan(φ1/2+Math.PI/4));
var θ = Math.atan2(Δλ, Δψ);
return (θ.toDegrees()+360) % 360;
};
/**
* Returns the destination point having travelled along a rhumb line from 'this' point the given
* distance on the given bearing.
*
* @param {number} distance - Distance travelled, in same units as earth radius (default: metres).
* @param {number} bearing - Bearing in degrees from north.
* @param {number} [radius=6371e3] - (Mean) radius of earth (defaults to radius in metres).
* @returns {LatLon} Destination point.
*
* @example
* var p1 = new LatLon(51.127, 1.338);
* var p2 = p1.rhumbDestinationPoint(40300, 116.7); // p2.toString(): 50.9642°N, 001.8530°E
*/
LatLon.prototype.rhumbDestinationPoint = function(distance, bearing, radius) {
radius = (radius === undefined) ? 6371e3 : Number(radius);
var δ = Number(distance) / radius; // angular distance in radians
var φ1 = this.lat.toRadians(), λ1 = this.lon.toRadians();
var θ = Number(bearing).toRadians();
var Δφ = δ * Math.cos(θ);
var φ2 = φ1 + Δφ;
// check for some daft bugger going past the pole, normalise latitude if so
if (Math.abs(φ2) > Math.PI/2) φ2 = φ2>0 ? Math.PI-φ2 : -Math.PI-φ2;
var Δψ = Math.log(Math.tan(φ2/2+Math.PI/4)/Math.tan(φ1/2+Math.PI/4));
var q = Math.abs(Δψ) > 10e-12 ? Δφ / Δψ : Math.cos(φ1); // E-W course becomes ill-conditioned with 0/0
var Δλ = δ*Math.sin(θ)/q;
var λ2 = λ1 + Δλ;
λ2 = (λ2 + 3*Math.PI) % (2*Math.PI) - Math.PI; // normalise to -180..+180°
return new LatLon(φ2.toDegrees(), λ2.toDegrees());
};
/**
* Returns the loxodromic midpoint (along a rhumb line) between 'this' point and second point.
*
* @param {LatLon} point - Latitude/longitude of second point.
* @returns {LatLon} Midpoint between this point and second point.
*
* @example
* var p1 = new LatLon(51.127, 1.338), p2 = new LatLon(50.964, 1.853);
* var p2 = p1.rhumbMidpointTo(p2); // p2.toString(): 51.0455°N, 001.5957°E
*/
LatLon.prototype.rhumbMidpointTo = function(point) {
if (!(point instanceof LatLon)) throw new TypeError('point is not LatLon object');
// http://mathforum.org/kb/message.jspa?messageID=148837
var φ1 = this.lat.toRadians(), λ1 = this.lon.toRadians();
var φ2 = point.lat.toRadians(), λ2 = point.lon.toRadians();
if (Math.abs(λ2-λ1) > Math.PI) λ1 += 2*Math.PI; // crossing anti-meridian
var φ3 = (φ1+φ2)/2;
var f1 = Math.tan(Math.PI/4 + φ1/2);
var f2 = Math.tan(Math.PI/4 + φ2/2);
var f3 = Math.tan(Math.PI/4 + φ3/2);
var λ3 = ( (λ2-λ1)*Math.log(f3) + λ1*Math.log(f2) - λ2*Math.log(f1) ) / Math.log(f2/f1);
if (!isFinite(λ3)) λ3 = (λ1+λ2)/2; // parallel of latitude
λ3 = (λ3 + 3*Math.PI) % (2*Math.PI) - Math.PI; // normalise to -180..+180°
return new LatLon(φ3.toDegrees(), λ3.toDegrees());
};
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/**
* Returns a string representation of 'this' point, formatted as degrees, degrees+minutes, or
* degrees+minutes+seconds.
*
* @param {string} [format=dms] - Format point as 'd', 'dm', 'dms'.
* @param {number} [dp=0|2|4] - Number of decimal places to use - default 0 for dms, 2 for dm, 4 for d.
* @returns {string} Comma-separated latitude/longitude.
*/
LatLon.prototype.toString = function(format, dp) {
if (format === undefined) format = 'dms';
return Dms.toLat(this.lat, format, dp) + ', ' + Dms.toLon(this.lon, format, dp);
};
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/** Extend Number object with method to convert numeric degrees to radians */
if (Number.prototype.toRadians === undefined) {
Number.prototype.toRadians = function() { return this * Math.PI / 180; };
}
/** Extend Number object with method to convert radians to numeric (signed) degrees */
if (Number.prototype.toDegrees === undefined) {
Number.prototype.toDegrees = function() { return this * 180 / Math.PI; };
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
if (typeof module != 'undefined' && module.exports) module.exports = LatLon; // CommonJS (Node)
if (typeof define == 'function' && define.amd) define(['Dms'], function() { return LatLon; }); // AMD
/* @license
PrayTimes.js: Prayer Times Calculator (ver 2.3)
Copyright (C) 2007-2011 PrayTimes.org
Developer: Hamid Zarrabi-Zadeh
License: GNU LGPL v3.0
TERMS OF USE:
Permission is granted to use this code, with or
without modification, in any website or application
provided that credit is given to the original work
with a link back to PrayTimes.org.
This program is distributed in the hope that it will
be useful, but WITHOUT ANY WARRANTY.
PLEASE DO NOT REMOVE THIS COPYRIGHT BLOCK.
*/
/*
Modifications by Emmanuel ATSE :
- Added calculation of midnight and last third of night
*/
//--------------------- Help and Manual ----------------------
/*
User's Manual:
http://praytimes.org/manual
Calculation Formulas:
http://praytimes.org/calculation
//------------------------ User Interface -------------------------
getTimes (date, coordinates [, timeZone [, dst [, timeFormat]]])
setMethod (method) // set calculation method
adjust (parameters) // adjust calculation parameters
tune (offsets) // tune times by given offsets
getMethod () // get calculation method
getSetting () // get current calculation parameters
getOffsets () // get current time offsets
//------------------------- Sample Usage --------------------------
var PT = new PrayTimes('ISNA');
var times = PT.getTimes(new Date(), [43, -80], -5);
document.write('Sunrise = '+ times.sunrise)
*/
//----------------------- PrayTimes Class ------------------------
function PrayTimes(method) {
//------------------------ Constants --------------------------
var
// Time Names
timeNames = {
imsak : 'Imsak',
fajr : 'Fajr',
sunrise : 'Sunrise',
dhuhr : 'Dhuhr',
asr : 'Asr',
sunset : 'Sunset',
maghrib : 'Maghrib',
isha : 'Isha',
midnight : 'Midnight',
lastThird : 'Last third of the night'
},
// Calculation Methods
methods = {
MWL: {
name: 'Muslim World League',
params: { fajr: 18, isha: 17 } },
ISNA: {
name: 'Islamic Society of North America (ISNA)',
params: { fajr: 15, isha: 15 } },
Egypt: {
name: 'Egyptian General Authority of Survey',
params: { fajr: 19.5, isha: 17.5 } },
Makkah: {
name: 'Umm Al-Qura University, Makkah',
params: { fajr: 18.5, isha: '90 min' } }, // fajr was 19 degrees before 1430 hijri
Karachi: {
name: 'University of Islamic Sciences, Karachi',
params: { fajr: 18, isha: 18 } },
Tehran: {
name: 'Institute of Geophysics, University of Tehran',
params: { fajr: 17.7, isha: 14, maghrib: 4.5, midnight: 'Jafari' } }, // isha is not explicitly specified in this method
Jafari: {
name: 'Shia Ithna-Ashari, Leva Institute, Qum',
params: { fajr: 16, isha: 14, maghrib: 4, midnight: 'Jafari' } }
},
// Default Parameters in Calculation Methods
defaultParams = {
maghrib: '0 min', midnight: 'Standard'
},
//----------------------- Parameter Values ----------------------
/*
// Asr Juristic Methods
asrJuristics = [
'Standard', // Shafi`i, Maliki, Ja`fari, Hanbali
'Hanafi' // Hanafi
],
// Midnight Mode
midnightMethods = [
'Standard', // Mid Sunset to Sunrise
'Jafari' // Mid Sunset to Fajr
],
// Adjust Methods for Higher Latitudes
highLatMethods = [
'NightMiddle', // middle of night
'AngleBased', // angle/60th of night
'OneSeventh', // 1/7th of night
'None' // No adjustment
],
// Time Formats
timeFormats = [
'24h', // 24-hour format
'12h', // 12-hour format
'12hNS', // 12-hour format with no suffix
'Float' // floating point number
],
*/
//---------------------- Default Settings --------------------
calcMethod = 'MWL',
// do not change anything here; use adjust method instead
setting = {
imsak : '10 min',
dhuhr : '0 min',
asr : 'Standard',
highLats : 'NightMiddle'
},
timeFormat = '24h',
timeSuffixes = ['am', 'pm'],
invalidTime = '-----',
numIterations = 1,
offset = {},
//----------------------- Local Variables ---------------------
lat, lng, elv, // coordinates
timeZone, jDate; // time variables
//---------------------- Initialization -----------------------
// set methods defaults
var defParams = defaultParams;
for (var i in methods) {
var params = methods[i].params;
for (var j in defParams)
if ((typeof(params[j]) == 'undefined'))
params[j] = defParams[j];
};
// initialize settings
calcMethod = methods[method] ? method : calcMethod;
var params = methods[calcMethod].params;
for (var id in params)
setting[id] = params[id];
// init time offsets
for (var i in timeNames)
offset[i] = 0;
//----------------------- Public Functions ------------------------
return {
// set calculation method
setMethod: function(method) {
if (methods[method]) {
this.adjust(methods[method].params);
calcMethod = method;
}
},
// set calculating parameters
adjust: function(params) {
for (var id in params)
setting[id] = params[id];
},
// set time offsets
tune: function(timeOffsets) {
for (var i in timeOffsets)
offset[i] = timeOffsets[i];
},
// get current calculation method
getMethod: function() { return calcMethod; },
// get current setting
getSetting: function() { return setting; },
// get current time offsets
getOffsets: function() { return offset; },
// get default calc parametrs
getDefaults: function() { return methods; },
// return prayer times for a given date
getTimes: function(date, coords, timezone, dst, format) {
lat = 1* coords[0];
lng = 1* coords[1];
elv = coords[2] ? 1* coords[2] : 0;
timeFormat = format || timeFormat;
if (date.constructor === Date)
date = [date.getFullYear(), date.getMonth()+ 1, date.getDate()];
if (typeof(timezone) == 'undefined' || timezone == 'auto')
timezone = this.getTimeZone(date);
if (typeof(dst) == 'undefined' || dst == 'auto')
dst = this.getDst(date);
timeZone = 1* timezone+ (1* dst ? 1 : 0);
jDate = this.julian(date[0], date[1], date[2])- lng/ (15* 24);
return this.computeTimes();
},
// convert float time to the given format (see timeFormats)
getFormattedTime: function(time, format, suffixes) {
if (isNaN(time))
return invalidTime;
if (format == 'Float') return time;
suffixes = suffixes || timeSuffixes;
time = DMath.fixHour(time+ 0.5/ 60); // add 0.5 minutes to round
var hours = Math.floor(time);
var minutes = Math.floor((time- hours)* 60);
var suffix = (format == '12h') ? suffixes[hours < 12 ? 0 : 1] : '';
var hour = (format == '24h') ? this.twoDigitsFormat(hours) : ((hours+ 12 -1)% 12+ 1);
return hour+ ':'+ this.twoDigitsFormat(minutes)+ (suffix ? ' '+ suffix : '');
},
//---------------------- Calculation Functions -----------------------
// compute mid-day time
midDay: function(time) {
var eqt = this.sunPosition(jDate+ time).equation;
var noon = DMath.fixHour(12- eqt);
return noon;
},
// compute the time at which sun reaches a specific angle below horizon
sunAngleTime: function(angle, time, direction) {
var decl = this.sunPosition(jDate+ time).declination;
var noon = this.midDay(time);
var t = 1/15* DMath.arccos((-DMath.sin(angle)- DMath.sin(decl)* DMath.sin(lat))/
(DMath.cos(decl)* DMath.cos(lat)));
return noon+ (direction == 'ccw' ? -t : t);
},
// compute asr time
asrTime: function(factor, time) {
var decl = this.sunPosition(jDate+ time).declination;
var angle = -DMath.arccot(factor+ DMath.tan(Math.abs(lat- decl)));
return this.sunAngleTime(angle, time);
},
// compute declination angle of sun and equation of time
// Ref: http://aa.usno.navy.mil/faq/docs/SunApprox.php
sunPosition: function(jd) {
var D = jd - 2451545.0;
var g = DMath.fixAngle(357.529 + 0.98560028* D);
var q = DMath.fixAngle(280.459 + 0.98564736* D);
var L = DMath.fixAngle(q + 1.915* DMath.sin(g) + 0.020* DMath.sin(2*g));
var R = 1.00014 - 0.01671* DMath.cos(g) - 0.00014* DMath.cos(2*g);
var e = 23.439 - 0.00000036* D;
var RA = DMath.arctan2(DMath.cos(e)* DMath.sin(L), DMath.cos(L))/ 15;
var eqt = q/15 - DMath.fixHour(RA);
var decl = DMath.arcsin(DMath.sin(e)* DMath.sin(L));
return {declination: decl, equation: eqt};
},
// convert Gregorian date to Julian day
// Ref: Astronomical Algorithms by Jean Meeus
julian: function(year, month, day) {
if (month <= 2) {
year -= 1;
month += 12;
};
var A = Math.floor(year/ 100);
var B = 2- A+ Math.floor(A/ 4);
var JD = Math.floor(365.25* (year+ 4716))+ Math.floor(30.6001* (month+ 1))+ day+ B- 1524.5;
return JD;
},
//---------------------- Compute Prayer Times -----------------------
// compute prayer times at given julian date
computePrayerTimes: function(times) {
times = this.dayPortion(times);
var params = setting;
var imsak = this.sunAngleTime(this.eval(params.imsak), times.imsak, 'ccw');
var fajr = this.sunAngleTime(this.eval(params.fajr), times.fajr, 'ccw');
var sunrise = this.sunAngleTime(this.riseSetAngle(), times.sunrise, 'ccw');
var dhuhr = this.midDay(times.dhuhr);
var asr = this.asrTime(this.asrFactor(params.asr), times.asr);
var sunset = this.sunAngleTime(this.riseSetAngle(), times.sunset);;
var maghrib = this.sunAngleTime(this.eval(params.maghrib), times.maghrib);
var isha = this.sunAngleTime(this.eval(params.isha), times.isha);
return {
imsak: imsak, fajr: fajr, sunrise: sunrise, dhuhr: dhuhr,
asr: asr, sunset: sunset, maghrib: maghrib, isha: isha
};
},
// compute prayer times
computeTimes: function() {
// default times
var times = {
imsak: 5, fajr: 5, sunrise: 6, dhuhr: 12,
asr: 13, sunset: 18, maghrib: 18, isha: 18
};
// main iterations
for (var i=1 ; i<=numIterations ; i++)
times = this.computePrayerTimes(times);
times.sunset += 3.0 / 60.0;
times = this.adjustTimes(times);
// add midnight time
times.midnight = (setting.midnight == 'Jafari') ?
times.sunset+ this.timeDiff(times.sunset, times.fajr)/ 2 :
times.sunset+ this.timeDiff(times.sunset, times.sunrise)/ 2;
// add last third of night time
times.lastThird = (setting.midnight == 'Jafari') ?
times.sunset + (this.timeDiff(times.sunset, times.fajr) / 3) * 2 :
times.sunset + (this.timeDiff(times.sunset, times.sunrise) / 3) * 2;
times = this.tuneTimes(times);
return this.modifyFormats(times);
},
// adjust times
adjustTimes: function(times) {
var params = setting;
for (var i in times)
times[i] += timeZone- lng/ 15;
if (params.highLats != 'None')
times = this.adjustHighLats(times);
if (this.isMin(params.imsak))
times.imsak = times.fajr- this.eval(params.imsak)/ 60;
if (this.isMin(params.maghrib))
times.maghrib = times.sunset+ this.eval(params.maghrib)/ 60;
if (this.isMin(params.isha))
times.isha = times.maghrib+ this.eval(params.isha)/ 60;
times.dhuhr += this.eval(params.dhuhr)/ 60;
return times;
},
// get asr shadow factor
asrFactor: function(asrParam) {
var factor = {Standard: 1, Hanafi: 2}[asrParam];
return factor || this.eval(asrParam);
},
// return sun angle for sunset/sunrise
riseSetAngle: function() {
//var earthRad = 6371009; // in meters
//var angle = DMath.arccos(earthRad/(earthRad+ elv));
var angle = 0.0347* Math.sqrt(elv); // an approximation
return 0.833+ angle;
},
// apply offsets to the times
tuneTimes: function(times) {
for (var i in times)
times[i] += offset[i]/ 60;
return times;
},
// convert times to given time format
modifyFormats: function(times) {
for (var i in times)
times[i] = this.getFormattedTime(times[i], timeFormat);
return times;
},
// adjust times for locations in higher latitudes
adjustHighLats: function(times) {
var params = setting;
var nightTime = this.timeDiff(times.sunset, times.sunrise);
times.imsak = this.adjustHLTime(times.imsak, times.sunrise, this.eval(params.imsak), nightTime, 'ccw');
times.fajr = this.adjustHLTime(times.fajr, times.sunrise, this.eval(params.fajr), nightTime, 'ccw');
times.isha = this.adjustHLTime(times.isha, times.sunset, this.eval(params.isha), nightTime);
times.maghrib = this.adjustHLTime(times.maghrib, times.sunset, this.eval(params.maghrib), nightTime);
return times;
},
// adjust a time for higher latitudes
adjustHLTime: function(time, base, angle, night, direction) {
var portion = this.nightPortion(angle, night);
var timeDiff = (direction == 'ccw') ?
this.timeDiff(time, base):
this.timeDiff(base, time);
if (isNaN(time) || timeDiff > portion)
time = base+ (direction == 'ccw' ? -portion : portion);
return time;
},
// the night portion used for adjusting times in higher latitudes
nightPortion: function(angle, night) {
var method = setting.highLats;
var portion = 1/2 // MidNight
if (method == 'AngleBased')
portion = 1/60* angle;
if (method == 'OneSeventh')
portion = 1/7;
return portion* night;
},
// convert hours to day portions
dayPortion: function(times) {
for (var i in times)
times[i] /= 24;
return times;
},
//---------------------- Time Zone Functions -----------------------
// get local time zone
getTimeZone: function(date) {
var year = date[0];
var t1 = this.gmtOffset([year, 0, 1]);
var t2 = this.gmtOffset([year, 6, 1]);
return Math.min(t1, t2);
},
// get daylight saving for a given date
getDst: function(date) {
return 1* (this.gmtOffset(date) != this.getTimeZone(date));
},
// GMT offset for a given date
gmtOffset: function(date) {
var localDate = new Date(date[0], date[1]- 1, date[2], 12, 0, 0, 0);
var GMTString = localDate.toGMTString();
var GMTDate = new Date(GMTString.substring(0, GMTString.lastIndexOf(' ')- 1));
var hoursDiff = (localDate- GMTDate) / (1000* 60* 60);
return hoursDiff;
},
//---------------------- Misc Functions -----------------------
// convert given string into a number
eval: function(str) {
return 1* (str+ '').split(/[^0-9.+-]/)[0];
},
// detect if input contains 'min'
isMin: function(arg) {
return (arg+ '').indexOf('min') != -1;
},
// compute the difference between two times
timeDiff: function(time1, time2) {
return DMath.fixHour(time2- time1);
},
// add a leading 0 if necessary
twoDigitsFormat: function(num) {
return (num <10) ? '0'+ num : num;
}
}}
//---------------------- Degree-Based Math Class -----------------------
var DMath = {