将双秒转换为分钟和几秒钟来计算步行/跑步速度 [英] Convert double to minutes and seconds to work out walking/running pace

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问题描述

我正在使用计时器来计算步行/跑步的速度，以获取经过的秒数，并使用距离计算器来计算距离，并使用速度=时间/距离的公式。使用下面的代码，它将每分钟的步速转换为2个小数位，每分钟最多.99。一切正常，但是我如何才能在几分钟和几秒钟内进行转换。谢谢

  public void calPace（）{
 
 double speed = 0; 
 
 progressTextView =（TextView）findViewById（R.id.paceTextView）; 
 
 if（chronometerOn）{
 
 int经过的时间Millis =（int）（SystemClock.elapsedRealtime（）-chronometer.getBase（））; 
 
 double activityTimeMins =（double）经过的英里/ 1000/60; 
 
 //仅在0.1英里后显示以加快速度
 if（totalDistance> 0.1）{
 
 speed = activityTimeMins / totalDistance; 
 
 progressTextView.setText（ Pace： + String.format（％。2f，步速）+ /英里）； 
 
}


解决方案

tl; dr 


 持续时间
 .between（
 start，
 Instant.now（）
）
 .dividedBy（laps）
 .toMinutes（）//渲染每分钟分钟数。 
 //和.toSecondsPart（）（或Java 8和Android早期的Android中的.toSeconds（）％60）


< h1> java.time

请勿自行计算日期时间数学。我们有针对该类的类。


捕获当前时间（以UTC表示），分辨率最高可达纳秒，但可能实时捕获的时间为毫秒或微秒。

 立即开始= Instant.now（）;

再次捕获当前时刻，最后。

 即时结束= Instant.now（）;

计算经过的时间。

 持续时间持续时间= Duration.between（start，end）;

询问其各个部分的持续时间：



  • 在Java 9+中，使用 toMinutes 方法获取总分钟数，并使用 toSecondsPart 方法获取秒数：


    I am working out the pace of a walk/run using my chronometer to get the elapsed seconds, and a distance calculator for distance and using the formulae pace = time/distance. Using the below code it converts the pace per minute into 2 decimal places up to .99 each minute. This is working fine but how can I convert this so it's in minutes and seconds. Thanks

    public void calPace(){

double pace = 0;
       
paceTextView = (TextView)findViewById(R.id.paceTextView);
      
if(chronometerOn) {
          
  int elapsedMillis = (int) (SystemClock.elapsedRealtime() - chronometer.getBase());
 
           double activityTimeMins = (double) elapsedMillis / 1000 / 60;
  
// only show after 0.1 mile to build pace up
  if(totalDistance>0.1){
             
        pace = activityTimeMins/totalDistance;

   paceTextView.setText("Pace : "+String.format("%.2f", pace)+" / mile");
      
  }

    解决方案

    tl;dr

    Duration
.between(
    start , 
    Instant.now()
)
.dividedBy( laps )
.toMinutes() // Renders minutes-per-lap.
// and .toSecondsPart() (or .toSeconds()%60 in Java 8 & early Android)

    java.time

    Do not roll-your-own date-time math. We have classes for that.

    Capture the current moment as seen in UTC, with a resolution up to nanoseconds, but likely captured live in either milliseconds or microseconds.

    Instant start = Instant.now() ;

    Capture the moment again, at the end.

    Instant end = Instant.now() ;

    Calculate elapsed time.

    Duration duration = Duration.between( start , end ) ;

    Interrogate the duration for its parts:

    • In Java 9+, use the toMinutes method for total minutes, and toSecondsPart method for seconds: Duration::toMinutes & Duration::toSecondsPart.
    • In Java 8 and early Android, we must do the math ourselves for the seconds by using modulo: Duration::toMinutes and Duration.toSeconds() % 60.

    Duration.dividedBy

    For your division (pace = activityTimeMins/totalDistance) we can use Duration.dividedBy to do the math.

    Take example the turtle race where the winner finished the 3 inch distance in 90 seconds. How many seconds per inch?

    Duration timePerInch = Duration.ofSeconds( 90 ).dividedBy( 3L ) ;

    PT30S

    ISO 8601

    The output shown there is in standard ISO 8601 format PnYnMnDTnHnMnS. The P marks the beginning. The T separates the years-month-days from the hours-minutes-seconds. So PT30S is a half minute.

    • Always use ISO 8601 formats when exchanging date-time values as text.
    • The formats may or may not be suitable for presentation to your users.

    Full example

    Pull that all together.

    Instant start = Instant.now() ;
…
Instant end = Instant.now() ;
Duration elapsed = Duration.between( start , end ) ;
int distance = … some number of laps, meters, miles, whatever.
Duration timePerDistanceUnit = elapsed.dividedBy( distance ) ; 
String message = 
    "Pace : " + 
    timePerDistanceUnit.toMinutes() + "m" +
    timePerDistanceUnit.toSecondsPart() + "s" +
    " per mile"
;

    If your distance (our divisor here) is fractional rather than an integer, you'll need to do a bit of the math yourself.

    Duration.ofNanos(
    Double
    .valueOf( 
        elapsed.toNanos() / 1.5   // For 1.5 miles as example distance.
    )  
    .longValue()  
);

    All together again.

    Instant start = Instant.now() ;
…
Instant end = Instant.now() ;
Duration elapsed = Duration.between( start , end ) ;
double distance = … some number of laps, meters, miles, whatever.
Duration timePerDistanceUnit = 
    Duration.ofNanos(
        Double.valueOf( elapsed.toNanos() / distance ).longValue()
    )
; 
String message = 
    "Pace : " + 
    timePerDistanceUnit.toMinutes() + "m" +
    timePerDistanceUnit.toSecondsPart() + "s" +
    " per mile"
;

    About java.time

    The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

    To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

    The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

    You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

    Where to obtain the java.time classes?

    这篇关于将双秒转换为分钟和几秒钟来计算步行/跑步速度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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