How can I get a numeric vector of time from two string vectors containing date and time?

Question

Emanuel Gunnarsson 2016-11-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/313237-how-can-i-get-a-numeric-vector-of-time-from-two-string-vectors-containing-date-and-time

编辑： Emanuel Gunnarsson 2016-11-22

I have data from Keysight benchvue and I tried first to export it to Matlab format but then the timestamp vector has values like

>> format long
>> Time_s(1)
ans =
       1.312396739146183e+17

which is far from what I would expect. This data was taken at 2016-11-18 19:29:51:461 and converting that to a numeric gives

>> datenum(2016,11,18,19,29,51.461)
ans =
       7.366528124011690e+05

I then tried to export it to csv-format instead and reading it with textscan. In that case I get two cell arrays, one containing the date and one containing the time. I don't understand how to use datevec to get the time as a numeric vector. I have tried

>> datevec(theContent{1} theContent{2})
   datevec(theContent{1} theContent{2})
                         ↑
  Error: Unexpected MATLAB expression.
where
>> theContent{1}(1)
ans = 
      '2016-11-18'
and
>> theContent{2}(1)
ans = 
      '19:29:51.461'
I also tried to concatenate the two arrays but then I get no blank space between them
>> strcat(theContent{1}(1),theContent{2}(1))
ans = 
      '2016-11-1819:29:51.461'

I guess (and hope) that this has a simple solution that some of You knows about.

Any suggestions are highly appreciated!

Thanks in advance!

Emanuel

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Walter Roberson 2016-11-21

This shows that the timestamps you are seeing are potentially in IEEE-1588 format. Unfortunately in the time I spent investigating, I did not figure out what the format is, exactly. No obvious conversion suggested itself.

Emanuel Gunnarsson 2016-11-21

编辑：Emanuel Gunnarsson 2016-11-22

Hi again Walter! Thanks for spending time on it! I accually saw the post You linked to yesterday, but as You say: one does not get any wiser from that.

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Answer 1

Preethi 2016-11-21

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/313237-how-can-i-get-a-numeric-vector-of-time-from-two-string-vectors-containing-date-and-time#answer_244097

在 MATLAB Online 中打开

hi,

use datenum and datevec

>> datevec(7.366528124011690e+05)
ans =
       2016           11           18           19           29       51.461
>> datetime(ans)
ans = 
   18-Nov-2016 19:29:51

hope this is useful.

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Preethi 2016-11-21

编辑：Preethi 2016-11-21

在 MATLAB Online 中打开

try

x = sprintf([theContent{1}(1),' ' ,theContent{2}(1)])

Emanuel Gunnarsson 2016-11-21

在 MATLAB Online 中打开

Hi again Preethi!

Yeah!! Thank You so much!

Apart from that the paranthesis should be changed to curly brakcets, this really solved it for me! Now I can do what You suggested:

>> x = sprintf([theContent{1}{1},' ' ,theContent{2}{1}])

x =

2016-11-18 19:29:51.461

>> datevec(x)

ans =

                      2016                        11                        18                        19                        29          51.4610000000102

Great!

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