Get duration of timerange

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Poison Idea fan 2023-3-13

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https://ww2.mathworks.cn/matlabcentral/answers/1928130-get-duration-of-timerange

评论： Poison Idea fan 2023-3-14

I have a timetable. I also have a timerange corresponding to data in that timetable. I am having a hard time thinking of how to get the length, or duration, of that timerange.

I feel it should be simple but I cannot think of a compact way to do it.

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Answer 1

Walter Roberson 2023-3-14

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https://ww2.mathworks.cn/matlabcentral/answers/1928130-get-duration-of-timerange#answer_1192375

在 MATLAB Online 中打开

R1 = timerange('2018-01-01','2018-05-01','quarters')

R1 =

timetable timerange subscript: Select timetable rows with times in: QUARTERS Starting at, including: 01-Jan-2018 00:00:00 Ending at, but excluding: 01-Jul-2018 00:00:00 See Select Times in Timetable.

R1S = struct(R1);

Warning: Calling STRUCT on an object prevents the object from hiding its implementation details and should thus be avoided. Use DISP or DISPLAY to see the visible public details of an object. See 'help struct' for more information.

R1S.first

ans = datetime

01-Jan-2018

R1S.last

ans = datetime

01-Jul-2018

R1S.unitOfTime

ans = 'quarters'

R1S.last - R1S.first

ans = duration

4344:00:00

R2 = timerange(seconds(2),seconds(4),'closed')

R2 =

timetable timerange subscript: Select timetable rows with times in the closed interval: [2 sec, 4 sec] See Select Times in Timetable.

R2S = struct(R2);

Warning: Calling STRUCT on an object prevents the object from hiding its implementation details and should thus be avoided. Use DISP or DISPLAY to see the visible public details of an object. See 'help struct' for more information.

R2S.first

ans = duration

2 sec

R2S.last

ans = duration

4 sec

R2S.unitOfTime

ans = 0×0 empty char array

R2S.last - R2S.first

ans = duration

2 sec

But what does the "length" or "duration" mean of a time range? In the case of a time range constructed from seconds it is fairly clear, but if the time range was constructed from quarter then do you need the "length" to be the number of quarters? If it was constructed from months do you need the length to be the number of months?

You can see in the quarters example that the difference between last and first is a duration, which by default gets expressed by hours minutes seconds. But because the range was constructed in quarters (a calendar duration) then looking at the duration in hours in misleading -- if you were to add that number of hours to a quarter at a different point in the year the end would probably not be the end of a quarter (quarters are not exactly equal length, and cannot be because 365 is not exactly divisible by 4)

You might have noticed the Warning message in the struct() call. timerange() does not expose any public methods or properties that allow you to get at the endpoint information, so you have to hack it.