计算两个坐标之间的距离从2列出了 [英] Calculate distance between two coordinates out of 2 lists

问题描述

我有一个问题。

我实现了谷歌地图在我的应用程序和保存我进入一个SQL数据库精简版的坐标（我也有一个开始和停止按钮）。现在我要计算的起点和终点之间的距离。我走出两个列表（一个用于Latidude，一个用于经度）和我的问题的坐标现在我怎么能遍历列表并获取坐标离开那里。我还需要一次，因为我需要开始和结束坐标也读出2个坐标，这我需要做的，直到列表完成。

所以，我希望有人知道这个问题的解决方案，这里是我的code：

 公共双calculateKM（）{
    allRoute =（ArrayList的＆LT;路线与GT;）db.getAllRouteByID（drive_id）;
    对于（路线路线：allRoute）{
        Log.d（汽车，route.getDate（））;
        lat.add（route.getLatitude（））; //这里我得到coordiantes从数据库中
        lon.add（route.getLongitude（））;        的for（int i = 0; I＆LT; lat.size（）;我++）{//这是我不能找到一个解决方案。
            字符串元素= lat.get（I）
            双值= Double.parseDouble（元）;        }
        calculateDistance（...）;
    }
}私人双calculateDistance（双fromLong，双fromLat，
            双toLong，双toLat）{        双D2R = Math.PI / 180;
        双dLong =（toLong  -  fromLong）* D2R;
        双DLAT =（toLat  -  fromLat）* D2R;
        双一= Math.pow（Math.sin（DLAT / 2.0），2）+ Math.cos（fromLat * D2R）
                * Math.cos（toLat * D2R）* Math.pow（Math.sin（dLong / 2.0），2）;
        双C = 2 * Math.atan2（的Math.sqrt（一）的Math.sqrt（1  -  a）条）;
        双D = 6367000 * C;
        返回Math.round（D）;    }
 

解决方案

  //创建任何包下保存的经度和纬度的一类
        私有类Cordinate
        {
        双拉提，隆基;        公共Cordinate（双LA，louble LO）
        {
           拉提= LA;
           隆基= LO;
        }
        //设置getter和setter这两个变量
        公共双getLati（）{
    返回LATI;
}公共无效setLati（双LATI）{
    this.lati = LATI;
}公共双getLongi（）{
    返回隆基;
}公共无效setLongi（双隆基）{
    this.longi =隆基;
}        }
        //定义数组列表保存的纬度和经度
        清单＆LT; Cordinate＆GT; cordinateList =新的ArrayList＆LT; Cordinate＆GT;（）;
        //那么你的functn内
        对于（路线路线：allRoute）{
                Log.d（汽车，route.getDate（））;                cordinateList.add（新Cordinate（route.getLattitude，rout.getLongitude））;
                的for（int i = 0; I＆LT; lat.size（）;我++）{//这是我不能找到一个解决方案。
                    字符串元素= lat.get（I）
                    双值= Double.parseDouble（元）;
                }
    //然后传递变量调用方法CalculateDistance（）
    //你可以使用cordinate变量设置位置对象
    为前//：loc.setLatitude（cordinateList（ⅰ）.getLati（））;
    // loc.setLatitude（cordinateList（ⅰ）.getLongi（））;
        //用于查找距离法
        CalculateDistance（位置LOC1，位置DEST）
        {
          双距离= DistanceCalculator.getDistance（LOC，DEST）;
                        距离= Math.round（距离* 100.0）/ 100.0;
        }
 

Hey guys i have a question.

I implemented Google Maps in my App and save the coordinates I get into an SQL Lite Database (I also have a Start and Stop button). Now I want to calculate the distance between the starting point and the end point. I get the coordinates out of two lists(one for Latidude and one for Longitude) and my problem now is how can I iterate through the list and get the coordinates out of there. I also need too read out 2 coordinates at once because I need the start and the end coordinates and this I need to do till the list is finished.

So I hope somebody knows a solution for this problem and here is my code:

public double calculateKM() {
    allRoute = (ArrayList<Route>) db.getAllRouteByID(drive_id);
    for (Route route : allRoute) {
        Log.d("Car: ", route.getDate());
        lat.add(route.getLatitude());//here I get the coordiantes out of the database
        lon.add(route.getLongitude());

        for (int i = 0; i < lat.size(); i++) {//and this is where I cant find a solution.
            String element = lat.get(i);
            double value = Double.parseDouble(element);



        }
        calculateDistance(...);


    }
}

private double calculateDistance(double fromLong, double fromLat,
            double toLong, double toLat) {

        double d2r = Math.PI / 180;
        double dLong = (toLong - fromLong) * d2r;
        double dLat = (toLat - fromLat) * d2r;
        double a = Math.pow(Math.sin(dLat / 2.0), 2) + Math.cos(fromLat * d2r)
                * Math.cos(toLat * d2r) * Math.pow(Math.sin(dLong / 2.0), 2);
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double d = 6367000 * c;
        return Math.round(d);

    }

解决方案

        //  create a class for saving latitude and longitude under any package
        private class Cordinate
        {
        double lati,longi;

        public Cordinate(double la,louble lo)
        {
           lati=la;
           longi=lo;
        }
        // set getters and setters for this two variables
        public double getLati() {
    return lati;
}

public void setLati(double lati) {
    this.lati = lati;
}

public double getLongi() {
    return longi;
}

public void setLongi(double longi) {
    this.longi = longi;
}



        }
        //define array list for saving the latitude and longitude
        List<Cordinate> cordinateList = new ArrayList<Cordinate>();


        // then inside your functn
        for (Route route : allRoute) {
                Log.d("Car: ", route.getDate());

                cordinateList.add(new Cordinate(route.getLattitude,rout.getLongitude));
                for (int i = 0; i < lat.size(); i++) {//and this is where I cant find a solution.
                    String element = lat.get(i);
                    double value = Double.parseDouble(element);
                }
    // then call the method CalculateDistance () by passing variables
    // You can use cordinate variables for setting the location object
    //  for ex: loc.setLatitude(cordinateList(i).getLati());
    //          loc.setLatitude(cordinateList(i).getLongi()); 


        // method for find distance
        CalculateDistance(Location loc1,Location dest)
        {
          double distance=DistanceCalculator.getDistance(loc, dest);
                        distance=Math.round(distance * 100.0) / 100.0;
        }

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