datetime - time only - 2016a

35 次查看（过去 30 天）
andytodd.msp
andytodd.msp 2020-9-7
评论： andytodd.msp 2020-9-7
Hi all, hope you are doing well!
I've got a question which I'm sure is very simple to anyone with any significant matlab experience!
I'm using 2016a, and am trying to filter some measuement data based on the date and time - for example, I want to compile all daytime data and all night time data into seperate graphs.
My issue is with the datetime command. when using the line of code below, is basically returns '0' for all entries, as the timedate command is including todays date - whereas the measurement data has been taken previously.
I have a 264x1 double containing all measurement values, and a 264x1 datetime with sample times - so if anyone can think of a simpler way for me to do this it would be greatly appreciated!
Thanks in advance for any help!
daytimeyn=timedate < (datetime('06:59:00','InputFormat','HH:mm:ss'))
nightla90=la90(daytimeyn==0);

请先登录，再回答此问题。

采纳的回答

Steven Lord
Steven Lord 2020-9-7
Use the timeofday function defined for datetime arrays.
>> timeofday(datetime('now')) % It is 3:12 PM as I type this
ans =
duration
15:12:56
Fifteen hours, twelve minutes, fifty-six seconds after midnight. Compare this against a duration, like check and see if this is between 9 AM and 5 PM:
>> is9To5 = @(t) hours(9) <= timeofday(t) & timeofday(t) <= hours(17);
>> is9To5(datetime('now')) % true as I type this
  2 个评论
Walter Roberson
Walter Roberson 2020-9-7
Another approach is
timedate - dateshift(timedate, 'start', 'day')
andytodd.msp
andytodd.msp 2020-9-7
Thank you both - thats great!
Steven, I found your method easier to implement, but thanks to you both for the help!
Andy

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Dates and Time 的更多信息

标签

产品


版本

R2016a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by