iOS找到平均速度 [英] iOS find average speed

问题描述

我已经有一些东西可以显示我当前的速度和最高速度（下面代码中的最大速度）现在我想制作能够计算核心位置的平均速度的东西。怎么样？谢谢。

I already have something that shows me my current speed and top speed (max speed in the code below) Now I want to make something that calculates my average speed with core location. How? thanks.

- (void)locationUpdate:(CLLocation *)location {
speedLabel.text = [NSString stringWithFormat:@"%.2f", [location speed]*2.236936284];

这是最高速度的浮动

   float currentSpeed = [location speed]*2.236936284;
if(currentSpeed - maxSpeed >= 0.01){
    maxSpeed = currentSpeed;
    maxspeedlabel.text = [NSString stringWithFormat: @"%.2f", maxSpeed];

}

推荐答案

声明变量是你的* .m类

Declare variable is your *.m class

@implementation your_class
{
    CLLocationDistance _distance;
    CLLocation *_lastLocation;
    NSDate *_startDate;
}

在 init 或 viewDidLoad 方法将它们设置为初始值

In your init or viewDidLoad method set them to initial values

_distance = 0;
_lastLocation = nil;
_startDate = nil;

将 locationUpdate：更改为

- (void)locationUpdate:(CLLocation *)location {
    speedLabel.text = [NSString stringWithFormat:@"%.2f", [location speed]*2.236936284];
    if (_startDate == nil) // first update!
    {
        _startDate = location.timestamp;
        _distance = 0;
    }
    else
    {
        _distance += [location distanceFromLocation:_lastLocation];
        _lastLocation = location;
        NSTimeInterval travelTime = [location.timestamp timeIntervalSinceDate:_startDate];
        if (travelTime > 0)
        {
            double avgSpeed = _distance / travelTime;
            AVGspeedlabel.text = [NSString stringWithFormat: @"%.2f", avgSpeed];
            NSLog(@"Average speed %.2f", avgSpeed);
        }
    }
}

重置平均速度

_startDate = nil;
_distance = 0;

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