我有多个纬度和经度,它们存储在我的SQLite数据库中,我想计算这些点的总距离。第一个位置到第二个位置再到第三个位置,都存储在数据库中。
从数据库中获取经纬度。
public ArrayList<Double> getPoints (){
ArrayList<Double> location = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("select latitude,longitude from "+Table_Name_Location,null);
if(cursor.getCount() > 0){
while (cursor.moveToNext()) {
Double latitude = cursor.getDouble(cursor.getColumnIndex("Lat"));
Double longitude = cursor.getDouble(cursor.getColumnIndex("Longi"));
location.add(latitude);
location.add(longitude);
}
}
cursor.close();
return location;
}
private double distance(double lat1, double lon1, double lat2, double lon2) {
double theta = lon1 - lon2;
double dist = Math.sin(deg2rad(lat1))
* Math.sin(deg2rad(lat2))
+ Math.cos(deg2rad(lat1))
* Math.cos(deg2rad(lat2))
* Math.cos(deg2rad(theta));
dist = Math.acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
return (dist);
}
private double deg2rad(double deg) {
return (deg * Math.PI / 180.0);
}
private double rad2deg(double rad) {
return (rad * 180.0 / Math.PI);
}
此方法的返回距离(以英里为单位)我检查了此函数的静态值lat和lon值。我想知道如何计算多个点之间的距离。
获取距离公里
private double distance(double lat1, double lon1, double lat2, double lon2) {
double theta = lon1 - lon2;
double dist = Math.sin(deg2rad(lat1))
* Math.sin(deg2rad(lat2))
+ Math.cos(deg2rad(lat1))
* Math.cos(deg2rad(lat2))
* Math.cos(deg2rad(theta));
dist = Math.acos(dist);
dist = rad2deg(dist);
dist = dist * 60 * 1.1515;
return (dist);
}
private double deg2rad(double deg) {
return (deg * Math.PI / 180.0);
}
private double rad2deg(double rad) {
return (rad * 180.0 / Math.PI);
}