如何计算用户从当前位置到iPhone特定位置的当前速度和平均速度？ [英] How to calculate the current speed and average speed of user travelling from current location to particular locaction in iPhone?

问题描述

我正在使用地图应用程序。当一个人从当前位置旅行到特定位置时，我想计算该人所覆盖的距离，该人的当前速度，该人的平均速度。

I am having a map application. When a person travels from current location to particular location I want to calculate the distance covered by the person, the current speed of the person, average speed of the person.

推荐答案

使用以下方法获取英里或公里的距离。你必须在头文件中声明计时器来合成它。

Use following methods to get distance in miles or kilometers. You have to declare timer in your header file synthesize it.

//SpeedViewController.h
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import <MobileCoreServices/UTCoreTypes.h>

@interface SpeedViewController : UIViewController <CLLocationManagerDelegate,UINavigationControllerDelegate>
{
    CLLocationManager *locManager;
    CLLocationSpeed speed;
    NSTimer *timer;

    CLLocationSpeed currentSpeed;
    float fltDistanceTravelled; 
}

@property (nonatomic,retain) NSTimer *timer;

-(float)getDistanceInKm:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation;
-(float)getDistanceInMiles:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation;

@end

//SpeedViewController.h
#import "SpeedViewController.h"
#define kRequiredAccuracy 500.0 //meters
#define kMaxAge 10.0 //seconds
#define M_PI   3.14159265358979323846264338327950288   /* pi */


@implementation SpeedViewController

@synthesize timer;
- (void)startReadingLocation {
    [locManager startUpdatingLocation];
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    CLLocationManager *locationManager=[[CLLocationManager alloc] init];
    locationManager.delegate=self;
    locationManager.desiredAccuracy=kCLLocationAccuracyBestForNavigation;
    [locationManager startUpdatingLocation];
}
- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc. that aren't in use.
}

- (void)viewDidUnload {
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [super dealloc];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{
    NSLog(@"new->%d old->%d",(newLocation==NULL),(oldLocation==NULL));

    if(newLocation && oldLocation)
    {
        fltDistanceTravelled +=[self getDistanceInKm:newLocation fromLocation:oldLocation];
    }
}

//this is a wrapper method to fit the required selector signature
- (void)timeIntervalEnded:(NSTimer*)timer {
    fltDistanceTravelled=0;
    [self startReadingLocation];
}


-(float)getDistanceInKm:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    float lat1,lon1,lat2,lon2;

    lat1 = newLocation.coordinate.latitude  * M_PI / 180;
    lon1 = newLocation.coordinate.longitude * M_PI / 180;

    lat2 = oldLocation.coordinate.latitude  * M_PI / 180;   
    lon2 = oldLocation.coordinate.longitude * M_PI / 180;

    float R = 6371; // km
    float dLat = lat2-lat1;
    float dLon = lon2-lon1; 

    float a = sin(dLat/2) * sin(dLat/2) + cos(lat1) * cos(lat2) * sin(dLon/2) * sin(dLon/2); 
    float c = 2 * atan2(sqrt(a), sqrt(1-a)); 
    float d = R * c;

    NSLog(@"Kms-->%f",d);

    return d;
}

-(float)getDistanceInMiles:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    float lat1,lon1,lat2,lon2;

    lat1 = newLocation.coordinate.latitude  * M_PI / 180;
    lon1 = newLocation.coordinate.longitude * M_PI / 180;

    lat2 = oldLocation.coordinate.latitude  * M_PI / 180;   
    lon2 = oldLocation.coordinate.longitude * M_PI / 180;

    float R = 3963; // km
    float dLat = lat2-lat1;
    float dLon = lon2-lon1; 

    float a = sin(dLat/2) * sin(dLat/2) + cos(lat1) * cos(lat2) * sin(dLon/2) * sin(dLon/2); 
    float c = 2 * atan2(sqrt(a), sqrt(1-a)); 
    float d = R * c;

    NSLog(@"Miles-->%f",d);

    return d;
}

@end

我还没有测试过这个设备，但逻辑上它应该工作。

I have not tested this on device but logically it should work.

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