Insert of discontinuous dates/time (yyyymmddhhmm) to the first column and filling of NAN to the second column which missing unknown field

I have 1 minutes frequency monthly data files. some  unknown field are missing due to not working of sensors.   I want to insert  new date/time (yyyymmddhhmm) filed to missing place(1st column)and  fill them with NAN. Highly appreciate your effort.

Answer 1

[Peter Perkins]

In recent versions of MATLAB:

>> t = readtable('Tide.txt','ReadVariableNames',false);
>> t.Properties.VariableNames = {'Time' 'X' 'Y'}
t =
  11×3 table
          Time            X        Y  
    ________________    _____    _____
    23/08/2017 00:00        4    2.044
    23/08/2017 00:01    4.001    2.046
    23/08/2017 00:03    4.007     2.05
    23/08/2017 00:04    4.009    2.054
    23/08/2017 00:07    4.017    2.061
    23/08/2017 00:08    4.019    2.063
    23/08/2017 00:09    4.022    2.065
    23/08/2017 00:10    4.023    2.067
    23/08/2017 00:11    4.026    2.069
    23/08/2017 00:13    4.028    2.072
    23/08/2017 00:14     4.03    2.074
>> tt = table2timetable(t)
tt =
  11×2 timetable
          Time            X        Y  
    ________________    _____    _____
    23/08/2017 00:00        4    2.044
    23/08/2017 00:01    4.001    2.046
    23/08/2017 00:03    4.007     2.05
    23/08/2017 00:04    4.009    2.054
    23/08/2017 00:07    4.017    2.061
    23/08/2017 00:08    4.019    2.063
    23/08/2017 00:09    4.022    2.065
    23/08/2017 00:10    4.023    2.067
    23/08/2017 00:11    4.026    2.069
    23/08/2017 00:13    4.028    2.072
    23/08/2017 00:14     4.03    2.074
>> tt = retime(tt,'minutely')
tt =
  15×2 timetable
          Time            X        Y  
    ________________    _____    _____
    23/08/2017 00:00        4    2.044
    23/08/2017 00:01    4.001    2.046
    23/08/2017 00:02      NaN      NaN
    23/08/2017 00:03    4.007     2.05
    23/08/2017 00:04    4.009    2.054
    23/08/2017 00:05      NaN      NaN
    23/08/2017 00:06      NaN      NaN
    23/08/2017 00:07    4.017    2.061
    23/08/2017 00:08    4.019    2.063
    23/08/2017 00:09    4.022    2.065
    23/08/2017 00:10    4.023    2.067
    23/08/2017 00:11    4.026    2.069
    23/08/2017 00:12      NaN      NaN
    23/08/2017 00:13    4.028    2.072
    23/08/2017 00:14     4.03    2.074

Or perhaps even

>> tt = retime(tt,'minutely','spline')
tt =
  15×2 timetable
          Time            X         Y   
    ________________    ______    ______
    23/08/2017 00:00         4     2.044
    23/08/2017 00:01     4.001     2.046
    23/08/2017 00:02     4.004    2.0475
    23/08/2017 00:03     4.007      2.05
    23/08/2017 00:04     4.009     2.054
    23/08/2017 00:05    4.0116    2.0571
    23/08/2017 00:06    4.0145    2.0592
    23/08/2017 00:07     4.017     2.061
    23/08/2017 00:08     4.019     2.063
    23/08/2017 00:09     4.022     2.065
    23/08/2017 00:10     4.023     2.067
    23/08/2017 00:11     4.026     2.069
    23/08/2017 00:12    4.0275    2.0705
    23/08/2017 00:13     4.028     2.072
    23/08/2017 00:14      4.03     2.074

Prior to R2016b, you'd have to do without timetables, and you may have to convert the first column of that file from text to datetime after reading. But you can recreate the call to retime using interp1.