Gis 与另一个有序对的给定距离“-可以有两个、一个或零：）这里可以找到一个比halversine更简单的函数。如果两个纬度不太远，可以使用这个函数！ function toRad(Value) { /** Converts numeric degrees

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与另一个有序对的给定距离“-可以有两个、一个或零：）这里可以找到一个比halversine更简单的函数。如果两个纬度不太远，可以使用这个函数！

function toRad(Value) {
    /** Converts numeric degrees to radians */
    return Value * Math.PI / 180;
}

/** returns the longitude a certain number of miles from another point given a latitude. **/
function getLon(miles, lat1, lat2, lon2) {
  // see http://www.movable-type.co.uk/scripts/latlong.html
  //Radius of the earth in:  1.609344 miles,  6371 km  | var R = (6371 / 1.609344);
    var R = 3958.7558657440545; // Radius of earth in Miles 
    miles = (typeof miles === "undefined") ? 1.46628357399041 : miles;
    lat1 = (typeof lat1 === "undefined") ? 42.34769 : lat1;
    lat2 = (typeof lat2 === "undefined") ? 42.367137 : lat2;
    lon2 = (typeof lon2 === "undefined") ? -71.124383 : lon2;
    var dLat =   toRad( lat2-lat1 );
    var sinInsideN1 = Math.sin(dLat);
    var sinInsideN2 = Math.sin(miles/2*R);
    var n1 = Math.pow(sinInsideN1,2);
    var n2 = Math.pow(sinInsideN2,2);
    var d1 = Math.cos(lat1)*Math.cos(lat2);
    var inArcsin = Math.sqrt((n2-n1)/d1);
    var translation = inArcsin-Math.floor(inArcsin);
    var ret = -(lat1+2*Math.asin(translation))
    return ret; // should be 42.34769
}

#include <math.h>

#define METERS_PER_DEGREE_EQUATOR 111319.5
#define MILES_PER_DEGREE_EQUATOR (METERS_PER_DEGREE_EQUATOR / 1000.0 / 1.609344)

/* Select preferred unit: */
#define UNITS_PER_DEGREE_EQUATOR MILES_PER_DEGREE_EQUATOR

double horDist(double lat1, double lon1, double lat2, double lon2)
    {
    /* From "Note on conversion from decimal degrees to meters"
     * (http://southport.jpl.nasa.gov/GRFM/cdrom/2a/DOCS/HTML/GEOLOC/METERS.HTM)
     * NOTE: BELOW IS ONLY PRECISE IF THE TWO LATITUDES ARE NOT TOO DISTANT! */
    double latDelta = UNITS_PER_DEGREE_EQUATOR * (lat1 - lat2);
    double lonDelta = UNITS_PER_DEGREE_EQUATOR * (lon1 - lon2) * cos(lat1 * M_PI / 180);
    return sqrt(latDelta * latDelta + lonDelta * lonDelta);
    }

double invHorDist_lon1(double lat1, double dist, double lat2, double lon2)
    {
    /* Rewrite horDist wrt lon1: */
    /* (dist * dist) = (latDelta * latDelta) + (lonDelta * lonDelta); */
    /* (dist * dist) - (latDelta * latDelta) = (lonDelta * lonDelta); */
    /* sqrt((dist * dist) - (latDelta * latDelta)) = lonDelta = UNITS_PER_DEGREE_EQUATOR * (lon1 - lon2) * cos(lat1 * M_PI / 180); */
    /* sqrt((dist * dist) - (latDelta * latDelta)) / UNITS_PER_DEGREE_EQUATOR / cos(lat1 * M_PI / 180) = (lon1 - lon2); */
    double latDelta = UNITS_PER_DEGREE_EQUATOR * (lat1 - lat2);
    return sqrt((dist * dist) - (latDelta * latDelta)) / UNITS_PER_DEGREE_EQUATOR / cos(lat1 * M_PI / 180) + lon2;
    }

int main()
    {
    double lon1 = invHorDist_lon1(42.34769, 1.46628357399041, 42.367137, -71.124383);
    printf("lon1 %f\n", lon1);
    printf("dist %f\n", horDist(42.34769, lon1, 42.367137, -71.124383));
    }

#include <math.h>

/*Earth Radius in Kilometers.*/
/* static const double R = 6372.797560856; */
/*Earth Radius in Miles.*/
static const double R = 3958.7558657440545;
/*Degree vs. Radian conservation variables*/
static const double DEG_TO_RAD = M_PI/180.0;
static const double RAD_TO_DEG = 180.0/M_PI;

double Haversine_Distance(double lat1,double lon1, double lat2, double lon2)
    {
    double dlon = (lon2 - lon1) * DEG_TO_RAD;
    double dlat = (lat2 - lat1) * DEG_TO_RAD;
    double a = pow(sin(dlat * 0.5),2) + cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD) * pow(sin(dlon * 0.5),2);
    double c = 2.0 * atan2(sqrt(a), sqrt(1-a));
    return R * c;
    }

double inverseHaversine_Distance_lon1(double lat1, double dist, double lat2, double lon2)
    {
    /* Rewrite Haversine_Distance wrt lon1: */
    /* dist = R * c = R * 2.0 * atan2(sqrt(a), sqrt(1-a)) */
    /* dist / R / 2.0 = atan2(sqrt(a), sqrt(1-a)) */
    /* sqrt(a) = sin(dist / R / 2.0); sqrt(1-a) = cos(dist / R / 2.0) */
    /* a = (sin(dist / R / 2.0))^2; 1 - a = (cos(dist / R / 2.0))^2 */
    /* pow(sin(dlat * 0.5),2) + cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD) * pow(sin(dlon * 0.5),2) = (sin(dist / R / 2.0))^2 */
    /* cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD) * pow(sin(dlon * 0.5),2) = (sin(dist / R / 2.0))^2 - pow(sin(dlat * 0.5),2) */
    /* pow(sin(dlon * 0.5),2) = (pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD))  */
    /* sin(dlon * 0.5) = sqrt((pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD))) */
    /* dlon = (lon2 - lon1) * DEG_TO_RAD = asin(sqrt((pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD)))) * 2.0 */
    /* lon2 - lon1 = asin(sqrt((pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD)))) * 2.0 / DEG_TO_RAD*/
    /* lon1 = lon2 - asin(sqrt((pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD)))) * 2.0 / DEG_TO_RAD*/
    double dlat = (lat2 - lat1) * DEG_TO_RAD;
    return lon2 - asin(sqrt((pow(sin(dist / R / 2.0), 2) - pow(sin(dlat * 0.5), 2)) / (cos(lat1*DEG_TO_RAD) * cos(lat2*DEG_TO_RAD)))) * 2.0 * RAD_TO_DEG;
    }

int main()
    {
    double lat1 = 42.34769;
    double dist = 1.46628357399041;
    double lat2 = 42.367137;
    double lon2 = -71.124383;
    double lon1 = inverseHaversine_Distance_lon1(lat1, dist, lat2, lon2);

    printf("lon1 %f\n", lon1);
    printf("dist %f\n", Haversine_Distance(lat1, lon1, lat2, lon2));
    }