Find average of collection of TimeSpans

问题

I have collection of TimeSpans, they represent time spent doing a task. Now I would like to find the average time spent on that task. It should be easy but for some reason I'm not getting the correct average.

Here's my code:

private TimeSpan? GetTimeSpanAverage(List<TimeSpan> sourceList)
{
    TimeSpan total = default(TimeSpan);

    var sortedDates = sourceList.OrderBy(x => x);

    foreach (var dateTime in sortedDates)
    {
        total += dateTime;
    }
    return TimeSpan.FromMilliseconds(total.TotalMilliseconds/sortedDates.Count());
}

回答1:

You can use the Average extension method:

double doubleAverageTicks = sourceList.Average(timeSpan => timeSpan.Ticks);
long longAverageTicks = Convert.ToInt64(doubleAverageTicks);

return new TimeSpan(longAverageTicks);

回答2:

var average = new TimeSpan(sourceList.Select(ts => ts.Ticks).Average());

---

Note, your method returns a Nullable, but doesn't need to, unless you want to return null if the source list is empty, in which case just do a separate check first.

回答3:

In Addition to the above answer, I would suggest you take an average on the Seconds or MilliSeconds level (depending on what you require)

sourceList.Average(timeSpan => timeSpan.ToTalMilliseconds)

Now using this value you could arrive at the new TimeSpan using

TimeSpan avg = TimeSpan.FromMilliseconds(double value here)

来源：https://stackoverflow.com/questions/8847679/find-average-of-collection-of-timespans