android 计算地图上两点距离的算法

android计算地图上两点距离的算法

接口：

package com.computedistance;public interface DistanceComputeInterface {    double getDistance(double lat1, double lng1, double lat2, double lng2);    double getShortDistance(double lat1, double lon1, double lat2, double lon2);    double getLongDistance(double lat1, double lon1, double lat2, double lon2);    double getDistanceBySpeed(double speed, double timeSpace);    double getAccurancyDistance(double lat_a, double lng_a, double lat_b, double lng_b);}

实现类：

package com.computedistance.impl;import java.security.InvalidParameterException;import com.baidu.mapapi.utils.DistanceUtil;import com.baidu.platform.comapi.basestruct.GeoPoint;import com.computedistance.DistanceComputeInterface;public class DistanceComputeImpl implements DistanceComputeInterface{    private final static double DEF_PI = 3.14159265359; // PI    private final static double DEF_2PI= 6.28318530712; // 2*PI    private final static double DEF_PI180= 0.01745329252; // PI/180.0    private final static double DEF_R =6370693.5; // radius of earth    private static DistanceComputeImpl instance = null;    public synchronized static DistanceComputeImpl getInstance(){        if (instance == null) {            instance = new DistanceComputeImpl();        }        return instance;    }    private DistanceComputeImpl(){}    @Override    public double getDistance(double lat1, double lng1, double lat2, double lng2) {        GeoPoint p1LL = new GeoPoint((int) (lat1*1e6), (int) (lng1*1e6));        GeoPoint p2LL = new GeoPoint((int) (lat2*1e6), (int) (lng2*1e6));        double distance = DistanceUtil.getDistance(p1LL, p2LL);        return distance/1000;    }    @Override    public double getShortDistance(double lat1, double lon1, double lat2,double lon2) {        double ew1, ns1, ew2, ns2;        double dx, dy, dew;        double distance;        // 角度转换为弧度        ew1 = lon1 * DEF_PI180;        ns1 = lat1 * DEF_PI180;        ew2 = lon2 * DEF_PI180;        ns2 = lat2 * DEF_PI180;        // 经度差        dew = ew1 - ew2;        // 若跨东经和西经180 度，进行调整        if (dew > DEF_PI)            dew = DEF_2PI - dew;        else if (dew < -DEF_PI)            dew = DEF_2PI + dew;        dx = DEF_R * Math.cos(ns1) * dew; // 东西方向长度(在纬度圈上的投影长度)        dy = DEF_R * (ns1 - ns2); // 南北方向长度(在经度圈上的投影长度)        // 勾股定理求斜边长        distance = Math.sqrt(dx * dx + dy * dy);        return distance/1000;    }    @Override    public double getLongDistance(double lat1, double lon1, double lat2,double lon2) {        double ew1, ns1, ew2, ns2;        double distance;        // 角度转换为弧度        ew1 = lon1 * DEF_PI180;        ns1 = lat1 * DEF_PI180;        ew2 = lon2 * DEF_PI180;        ns2 = lat2 * DEF_PI180;        // 求大圆劣弧与球心所夹的角(弧度)        distance = Math.sin(ns1) * Math.sin(ns2) + Math.cos(ns1) * Math.cos(ns2) * Math.cos(ew1 - ew2);        // 调整到[-1..1]范围内，避免溢出        if (distance > 1.0){            distance = 1.0;        } else if (distance < -1.0){            distance = -1.0;        }        // 求大圆劣弧长度        distance = DEF_R * Math.acos(distance);        return distance/1000;    }    @Override    public double getDistanceBySpeed(double speed, double timeSpace) {        if (speed  < 0 || timeSpace <= 0) {            throw new InvalidParameterException();        }        return speed * timeSpace;    }    @Override    public double getAccurancyDistance(double lat_a, double lng_a,double lat_b, double lng_b) {        double pk = (double) (180 / 3.14169);        double a1 = lat_a / pk;        double a2 = lng_a / pk;        double b1 = lat_b / pk;        double b2 = lng_b / pk;        double t1 = Math.cos(a1) * Math.cos(a2) * Math.cos(b1) * Math.cos(b2);        double t2 = Math.cos(a1) * Math.sin(a2) * Math.cos(b1) * Math.sin(b2);        double t3 = Math.sin(a1) * Math.sin(b1);        double tt = Math.acos(t1 + t2 + t3);        return 6366000 * tt / 1000;    }}

附：android中使用百度定位sdk实时的计算移动距离

更多相关文章

随机推荐