191 lines
6.9 KiB
JavaScript
191 lines
6.9 KiB
JavaScript
/**
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* dms module
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* @module dms
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*/
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// Just return a value to define the module export.
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// This example returns an object, but the module
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// can return a function as the exported value.
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// Matches DMS DmsCoordinates
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// http://regexpal.com/?flags=gim®ex=^%28-%3F\d%2B%28%3F%3A\.\d%2B%29%3F%29[%C2%B0%3Ad]%3F\s%3F%28%3F%3A%28\d%2B%28%3F%3A\.\d%2B%29%3F%29[%27%E2%80%B2%3A]%3F\s%3F%28%3F%3A%28\d%2B%28%3F%3A\.\d%2B%29%3F%29[%22%E2%80%B3]%3F%29%3F%29%3F\s%3F%28[NSEW]%29%3F&input=40%3A26%3A46N%2C79%3A56%3A55W%0A40%3A26%3A46.302N%2079%3A56%3A55.903W%0A40%C2%B026%E2%80%B247%E2%80%B3N%2079%C2%B058%E2%80%B236%E2%80%B3W%0A40d%2026%E2%80%B2%2047%E2%80%B3%20N%2079d%2058%E2%80%B2%2036%E2%80%B3%20W%0A40.446195N%2079.948862W%0A40.446195%2C%20-79.948862%0A40%C2%B0%2026.7717%2C%20-79%C2%B0%2056.93172%0A
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const dmsRe = /^(-?\d+(?:\.\d+)?)[°:d]?\s?(?:(\d+(?:\.\d+)?)['′ʹ:]?\s?(?:(\d+(?:\.\d+)?)["″ʺ]?)?)?\s?([NSEW])?/i;
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/**
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* Removes the decimal part of a number without rounding up.
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* @param {number} n
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* @returns {number}
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* @private
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*/
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function truncate(n) {
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return n > 0 ? Math.floor(n) : Math.ceil(n);
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}
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export class Dms {
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_dd;
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_hemisphere;
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/**
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* Value in decimal degrees
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* @member {number}
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* @readonly
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*/
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get dd() {
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return this._dd;
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}
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/**
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* Hemisphere
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* @member {string}
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* @readonly
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*/
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get hemisphere() {
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return this._hemisphere;
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}
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/**
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* @constructor module:dms.Dms
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* @param {number} dd
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* @param {string} longOrLat
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*/
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constructor(dd, longOrLat) {
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this._dd = dd;
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this._hemisphere = /^[WE]|(?:lon)/i.test(longOrLat) ? dd < 0 ? "W" : "E" : dd < 0 ? "S" : "N";
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}
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/**
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* Returns the DMS parts as an array.
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* The first three elements of the returned array are numbers:
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* degrees, minutes, and seconds respectively. The fourth
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* element is a string indicating the hemisphere: "N", "S", "E", or "W".
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* @returns {Array.<(number|string)>}
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* @deprecated
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*/
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getDmsArray() {
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return this.dmsArray;
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}
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/**
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* Returns the DMS parts as an array.
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* The first three elements of the returned array are numbers:
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* degrees, minutes, and seconds respectively. The fourth
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* element is a string indicating the hemisphere: "N", "S", "E", or "W".
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* @returns {Array.<(number|string)>}
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*/
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get dmsArray() {
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const absDD = Math.abs(this._dd);
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const degrees = truncate(absDD);
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const minutes = truncate((absDD - degrees) * 60);
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const seconds = (absDD - degrees - minutes / 60) * Math.pow(60, 2);
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return [degrees, minutes, seconds, this._hemisphere];
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}
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/**
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* Returns the DMS value as a string.
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* @param {number} [precision] - number of digits after the decimal point in seconds
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* @returns {string}
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*/
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toString(precision) {
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const dmsArray = this.getDmsArray();
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const second = isNaN(Number(precision)) ? dmsArray[2] : dmsArray[2].toFixed(precision);
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return `${dmsArray[0]}°${dmsArray[1]}′${second}″ ${dmsArray[3]}`;
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}
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}
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/**
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* @typedef {Object} DmsArrays
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* @property {Array.<(number|string)>} longitude
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* @property {Array.<(number|string)>} latitude
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*/
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export default class DmsCoordinates {
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lat;
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lon;
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// Results of match will be [full coords string, Degrees, minutes (if any), seconds (if any), hemisphere (if any)]
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// E.g., ["40:26:46.302N", "40", "26", "46.302", "N"]
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// E.g., ["40.446195N", "40.446195", undefined, undefined, "N"]
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/**
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* A regular expression matching DMS coordinate.
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* Example matches:
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* E.g., ["40:26:46.302N", "40", "26", "46.302", "N"]
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* E.g., ["40.446195N", "40.446195", undefined, undefined, "N"]
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* @type {RegExp}
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* @static
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*/
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static dmsRe = dmsRe;
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_longitude;
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_latitude;
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/**
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* Longitude
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* @type {module:dms.Dms} longitude - Longitude (X coordinate);
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*/
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get longitude() {
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return this._longitude;
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}
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/**
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* Latitude
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* @type {module:dms.Dms} longitude - Latitude (y coordinate);
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*/
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get latitude() {
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return this._latitude;
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}
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/**
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* Represents a location on the earth in WGS 1984 coordinates.
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* @constructor module:dms.DmsCoordinates
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* @param {number} latitude - WGS 84 Y coordinates
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* @param {number} longitude - WGS 84 X coordinates
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* @throws {TypeError} - latitude and longitude must be numbers.
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* @throws {RangeError} - latitude must be between -180 and 180, and longitude between -90 and 90. Neither can be NaN.
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*/
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constructor(lat, lon) {
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this.lat = lat;
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this.lon = lon;
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if (typeof lat !== "number" || typeof lon !== "number") {
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throw TypeError("The longitude and latitude parameters must be numbers.");
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}
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if (isNaN(lon) || lon < -180 || lon > 180) {
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throw RangeError("longitude must be between -180 and 180");
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}
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if (isNaN(lat) || lat < -90 || lat > 90) {
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throw RangeError("latitude must be between -90 and 90");
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}
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this._longitude = new Dms(lon, "long");
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this._latitude = new Dms(lat, "lat");
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}
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/**
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* Returns an object containing arrays containing degree / minute / second components.
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* @returns {DmsArrays}
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* @deprecated
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*/
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getDmsArrays() {
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return this.dmsArrays;
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}
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/**
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* Returns an object containing arrays containing degree / minute / second components.
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* @type {DmsArrays}
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*/
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get dmsArrays() {
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return {
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longitude: this.longitude.dmsArray,
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latitude: this.latitude.dmsArray,
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};
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}
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/**
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* Returns the coordinates to a comma-separated string.
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* @returns {string}
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*/
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toString() {
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return [this.latitude, this.longitude].join(", ");
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}
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}
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/**
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* Parses a Degrees Minutes Seconds string into a Decimal Degrees number.
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* @param {string} dmsStr A string containing a coordinate in either DMS or DD format.
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* @return {Number} If dmsStr is a valid coordinate string, the value in decimal degrees will be returned. Otherwise NaN will be returned.
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*/
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export function parseDms(dmsStr) {
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let output = NaN;
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const dmsMatch = dmsRe.exec(dmsStr);
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if (dmsMatch) {
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const degrees = Number(dmsMatch[1]);
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const minutes = typeof (dmsMatch[2]) !== "undefined" ? Number(dmsMatch[2]) / 60 : 0;
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const seconds = typeof (dmsMatch[3]) !== "undefined" ? Number(dmsMatch[3]) / 3600 : 0;
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const hemisphere = dmsMatch[4] || null;
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if (hemisphere !== null && /[SW]/i.test(hemisphere)) {
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output = -Math.abs(degrees) - minutes - seconds;
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}
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else {
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output = degrees + minutes + seconds;
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}
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}
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return output;
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}
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