Hourly and 6-hourly average of data in timeable

How would I take an hourly and 6-hourly average of this data?

IM1TT =

  2899×2 table

        Date & Time         IM1 Stress
    ____________________    __________

    31-May-2010 14:50:00           NaN
    31-May-2010 15:00:00           NaN
    31-May-2010 15:10:00           6.9
    31-May-2010 15:20:00           2.1
    31-May-2010 15:30:00           6.3
    31-May-2010 15:40:00           5.2
    31-May-2010 15:50:00           NaN
    31-May-2010 16:00:00           NaN
    31-May-2010 16:10:00           3.2
    31-May-2010 16:20:00           NaN

Answer 1

[Eric Sofen]

If you want the rolling average, use smoothdata, with 'movmean' as the method and (e.g.) hours(6) as the window. If you want non-overlapping hourly/6-hourly averages, use retime. There will be two different ways to use retime, as hourly averaging is built-in:

retime(tt,'hourly','mean')

whereas you'll want to specify the time vector or timestep for the 6-hour averages. If you just specify the timestep, the 6-hour bins start from the start of your data:

retime(tt,'regular','mean','TimeStep',hours(6))

or

retime(tt,datetime(2010,5,31,12,0,0):hours(6):<whatever end time>,'mean')

Answer 2

[Mischa Kim]

Phoebe, it looks like your data points are all equally spaced(?), 10 minutes. Check out the movmean() command.