function getMeanLineString(centroidOfLine: number[], angle: number, lenOfLine: number, isPlanar: boolean) {
    if (isPlanar) {
        const [averageX, averageY]: number[] = centroidOfLine;
        let beginX: number;
        let beginY: number;
        let endX: number;
        let endY: number;
        const r: number = angle * Math.PI / 180;
        const sin: number = Math.sin(r);
        const cos: number = Math.cos(r);
        beginX = averageX - lenOfLine / 2 * cos;
        beginY = averageY - lenOfLine / 2 * sin;
        endX = averageX + lenOfLine / 2 * cos;
        endY = averageY + lenOfLine / 2 * sin;
        return [
            [beginX, beginY],
            [endX, endY],
        ];
    } else {
        const end = destination(point(centroidOfLine), lenOfLine / 2, angle, { units: "meters" });
        const begin = destination(point(centroidOfLine), -lenOfLine / 2, angle, { units: "meters" });
        return [
            getCoord(begin), getCoord(end),
        ];
    }
}

/**
 * Takes two {@link Point|points} and finds the bearing angle between them along a Rhumb line
 * i.e. the angle measured in degrees start the north line (0 degrees)
 *
 * @name rhumbBearing
 * @param {Coord} start starting Point
 * @param {Coord} end ending Point
 * @param {Object} [options] Optional parameters
 * @param {boolean} [options.final=false] calculates the final bearing if true
 * @returns {number} bearing from north in decimal degrees, between -180 and 180 degrees (positive clockwise)
 * @example
 * var point1 = turf.point([-75.343, 39.984], {"marker-color": "#F00"});
 * var point2 = turf.point([-75.534, 39.123], {"marker-color": "#00F"});
 *
 * var bearing = turf.rhumbBearing(point1, point2);
 *
 * //addToMap
 * var addToMap = [point1, point2];
 * point1.properties.bearing = bearing;
 * point2.properties.bearing = bearing;
 */
function rhumbBearing(start: Coord, end: Coord, options: {final?: boolean} = {}): number {
    let bear360;
    if (options.final) { bear360 = calculateRhumbBearing(getCoord(end), getCoord(start));
    } else { bear360 = calculateRhumbBearing(getCoord(start), getCoord(end)); }

    const bear180 = (bear360 > 180) ? - (360 - bear360) : bear360;

    return bear180;
}

export function pNormDistance(feature1: Feature<Point>, feature2: Feature<Point>, p: number = 2): number {
  const coordinate1 = getCoord(feature1);
  const coordinate2 = getCoord(feature2);
  const xDiff = coordinate1[0] - coordinate2[0];
  const yDiff = coordinate1[1] - coordinate2[1];
  if (p === 1) {
    return Math.abs(xDiff) + Math.abs(yDiff);
  }
  return Math.pow((Math.pow(xDiff, p) + Math.pow(yDiff, p)), 1 / p);
}

/**
 * Calculates the distance along a rhumb line between two {@link Point|points} in degrees, radians,
 * miles, or kilometers.
 *
 * @name rhumbDistance
 * @param {Coord} from origin point
 * @param {Coord} to destination point
 * @param {Object} [options] Optional parameters
 * @param {string} [options.units="kilometers"] can be degrees, radians, miles, or kilometers
 * @returns {number} distance between the two points
 * @example
 * var from = turf.point([-75.343, 39.984]);
 * var to = turf.point([-75.534, 39.123]);
 * var options = {units: 'miles'};
 *
 * var distance = turf.rhumbDistance(from, to, options);
 *
 * //addToMap
 * var addToMap = [from, to];
 * from.properties.distance = distance;
 * to.properties.distance = distance;
 */
function rhumbDistance(from: Coord, to: Coord, options: {
    units?: Units,
} = {}): number {
    const origin = getCoord(from);
    const destination = getCoord(to);

    // compensate the crossing of the 180th meridian (https://macwright.org/2016/09/26/the-180th-meridian.html)
    // solution from https://github.com/mapbox/mapbox-gl-js/issues/3250#issuecomment-294887678
    destination[0] += (destination[0] - origin[0] > 180) ? -360 : (origin[0] - destination[0] > 180) ? 360 : 0;
    const distanceInMeters = calculateRhumbDistance(origin, destination);
    const distance = convertLength(distanceInMeters, "meters", options.units);
    return distance;
}

//http://en.wikipedia.org/wiki/Haversine_formula
//http://www.movable-type.co.uk/scripts/latlong.html

/**
 * Calculates the distance between two {@link Point|points} in degrees, radians, miles, or kilometers.
 * This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
 *
 * @name distance
 * @param {Coord} from origin point
 * @param {Coord} to destination point
 * @param {Object} [options={}] Optional parameters
 * @param {string} [options.units='kilometers'] can be degrees, radians, miles, or kilometers
 * @returns {number} distance between the two points
 * @example
 * var from = turf.point([-75.343, 39.984]);
 * var to = turf.point([-75.534, 39.123]);
 * var options = {units: 'miles'};
 *
 * var distance = turf.distance(from, to, options);
 *
 * //addToMap
 * var addToMap = [from, to];
 * from.properties.distance = distance;
 * to.properties.distance = distance;
 */
function distance(from: Coord, to: Coord, options: {
    units?: Units,
} = {}) {
    var coordinates1 = getCoord(from);
    var coordinates2 = getCoord(to);
    var dLat = degreesToRadians((coordinates2[1] - coordinates1[1]));
    var dLon = degreesToRadians((coordinates2[0] - coordinates1[0]));
    var lat1 = degreesToRadians(coordinates1[1]);
    var lat2 = degreesToRadians(coordinates2[1]);

    var a = Math.pow(Math.sin(dLat / 2), 2) +
          Math.pow(Math.sin(dLon / 2), 2) * Math.cos(lat1) * Math.cos(lat2);

    return radiansToLength(2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)), options.units);
}

/**
 * Takes a {@link Point} and calculates the location of a destination point given a distance in
 * degrees, radians, miles, or kilometers; and bearing in degrees.
 * This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
 *
 * @name destination
 * @param {Coord} origin starting point
 * @param {number} distance distance from the origin point
 * @param {number} bearing ranging from -180 to 180
 * @param {Object} [options={}] Optional parameters
 * @param {string} [options.units='kilometers'] miles, kilometers, degrees, or radians
 * @param {Object} [options.properties={}] Translate properties to Point
 * @returns {Feature<Point>} destination point
 * @example
 * var point = turf.point([-75.343, 39.984]);
 * var distance = 50;
 * var bearing = 90;
 * var options = {units: 'miles'};
 *
 * var destination = turf.destination(point, distance, bearing, options);
 *
 * //addToMap
 * var addToMap = [point, destination]
 * destination.properties['marker-color'] = '#f00';
 * point.properties['marker-color'] = '#0f0';
 */
export default function destination<P = Properties>(
    origin: Coord,
    distance: number,
    bearing: number,
    options: {
        units?: Units,
        properties?: P,
    } = {},
): Feature<Point, P> {
    // Handle input
    const coordinates1 = getCoord(origin);
    const longitude1 = degreesToRadians(coordinates1[0]);
    const latitude1 = degreesToRadians(coordinates1[1]);
    const bearingRad = degreesToRadians(bearing);
    const radians = lengthToRadians(distance, options.units);

    // Main
    const latitude2 = Math.asin(Math.sin(latitude1) * Math.cos(radians) +
        Math.cos(latitude1) * Math.sin(radians) * Math.cos(bearingRad));
    const longitude2 = longitude1 + Math.atan2(Math.sin(bearingRad) * Math.sin(radians) * Math.cos(latitude1),
        Math.cos(radians) - Math.sin(latitude1) * Math.sin(latitude2));
    const lng = radiansToDegrees(longitude2);
    const lat = radiansToDegrees(latitude2);

    return point([lng, lat], options.properties);
}

// http://en.wikipedia.org/wiki/Haversine_formula
// http://www.movable-type.co.uk/scripts/latlong.html

/**
 * Takes two {@link Point|points} and finds the geographic bearing between them,
 * i.e. the angle measured in degrees from the north line (0 degrees)
 *
 * @name bearing
 * @param {Coord} start starting Point
 * @param {Coord} end ending Point
 * @param {Object} [options={}] Optional parameters
 * @param {boolean} [options.final=false] calculates the final bearing if true
 * @returns {number} bearing in decimal degrees, between -180 and 180 degrees (positive clockwise)
 * @example
 * var point1 = turf.point([-75.343, 39.984]);
 * var point2 = turf.point([-75.534, 39.123]);
 *
 * var bearing = turf.bearing(point1, point2);
 *
 * //addToMap
 * var addToMap = [point1, point2]
 * point1.properties['marker-color'] = '#f00'
 * point2.properties['marker-color'] = '#0f0'
 * point1.properties.bearing = bearing
 */
export default function bearing(start: Coord, end: Coord, options: {
    final?: boolean,
} = {}): number {
    // Reverse calculation
    if (options.final === true) { return calculateFinalBearing(start, end); }

    const coordinates1 = getCoord(start);
    const coordinates2 = getCoord(end);

    const lon1 = degreesToRadians(coordinates1[0]);
    const lon2 = degreesToRadians(coordinates2[0]);
    const lat1 = degreesToRadians(coordinates1[1]);
    const lat2 = degreesToRadians(coordinates2[1]);
    const a = Math.sin(lon2 - lon1) * Math.cos(lat2);
    const b = Math.cos(lat1) * Math.sin(lat2) -
        Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1);

    return radiansToDegrees(Math.atan2(a, b));
}

/**
 * Returns the destination {@link Point} having travelled the given distance along a Rhumb line from the
 * origin Point with the (varant) given bearing.
 *
 * @name rhumbDestination
 * @param {Coord} origin starting point
 * @param {number} distance distance from the starting point
 * @param {number} bearing varant bearing angle ranging from -180 to 180 degrees from north
 * @param {Object} [options={}] Optional parameters
 * @param {string} [options.units='kilometers'] can be degrees, radians, miles, or kilometers
 * @param {Object} [options.properties={}] translate properties to destination point
 * @returns {Feature<Point>} Destination point.
 * @example
 * var pt = turf.point([-75.343, 39.984], {"marker-color": "F00"});
 * var distance = 50;
 * var bearing = 90;
 * var options = {units: 'miles'};
 *
 * var destination = turf.rhumbDestination(pt, distance, bearing, options);
 *
 * //addToMap
 * var addToMap = [pt, destination]
 * destination.properties['marker-color'] = '#00F';
 */
function rhumbDestination<P = Properties>(origin: Coord, distance: number, bearing: number, options: {
    units?: Units,
    properties?: P,
} = {}): Feature<Point, P> {
    
    const wasNegativeDistance = distance < 0;
    let distanceInMeters = convertLength(Math.abs(distance), options.units, "meters");
    if (wasNegativeDistance) distanceInMeters = -Math.abs(distanceInMeters);
    const coords = getCoord(origin);
    const destination = calculateRhumbDestination(coords, distanceInMeters, bearing);

    // compensate the crossing of the 180th meridian (https://macwright.org/2016/09/26/the-180th-meridian.html)
    // solution from https://github.com/mapbox/mapbox-gl-js/issues/3250#issuecomment-294887678
    destination[0] += (destination[0] - coords[0] > 180) ? -360 : (coords[0] - destination[0] > 180) ? 360 : 0;
    return point(destination, options.properties);
}

/**
 * Returns true if a point is on a line. Accepts a optional parameter to ignore the
 * start and end vertices of the linestring.
 *
 * @name booleanPointOnLine
 * @param {Coord} pt GeoJSON Point
 * @param {Feature<LineString>} line GeoJSON LineString
 * @param {Object} [options={}] Optional parameters
 * @param {boolean} [options.ignoreEndVertices=false] whether to ignore the start and end vertices.
 * @returns {boolean} true/false
 * @example
 * var pt = turf.point([0, 0]);
 * var line = turf.lineString([[-1, -1],[1, 1],[1.5, 2.2]]);
 * var isPointOnLine = turf.booleanPointOnLine(pt, line);
 * //=true
 */
function booleanPointOnLine(pt: Coord, line: Feature<LineString> | LineString, options: {
    ignoreEndVertices?: boolean,
} = {}): boolean {
    // Normalize inputs
    const ptCoords = getCoord(pt);
    const lineCoords = getCoords(line);

    // Main
    for (let i = 0; i < lineCoords.length - 1; i++) {
        let ignoreBoundary: boolean|string = false;
        if (options.ignoreEndVertices) {
            if (i === 0) { ignoreBoundary = "start"; }
            if (i === lineCoords.length - 2) { ignoreBoundary = "end"; }
            if (i === 0 && i + 1 === lineCoords.length - 1) { ignoreBoundary = "both"; }
        }
        if (isPointOnLineSegment(lineCoords[i], lineCoords[i + 1], ptCoords, ignoreBoundary)) { return true; }
    }
    return false;
}