How can I retime my timetable with a 10days timestep?

Hi guys,

I need to retime my hourly timetable to an average 10days time step. Then apply an index to them.

I know that predefine timesteps like hourly or monthly exist in m,atlab but 10day time interval??

Thanks in advance

Answer 1

[dpb]

Read the documentation...

TT2 = retime(TT1,'regular',method,'TimeStep',dt) calculates regularly spaced row times using the time step dt. The dt input argument is a scalar duration or calendar duration, specifying a time step of any size. The row times of TT2 span the range of row times of TT1.

Use this syntax when the time step is not one of the predefined time steps you can specify as a character vector or string.

[Hamed Hedayatnia]

I read it but i could not find out how can i put 10days in the code and define mean.

[dpb]

Ewww....by bad. I misinterpreted the doc myself. I didn't realize retime doesn't allow an aggregation method with a dt specification instead of a full new time vector first.

See Steven's answer instead.

The former seems a shortcoming in implementation altho not a bug since does not promis that can...

[Peter Perkins]

It does, actually, unless I'm misunderstanding:

>> tt = timetable(rand(25,1),'RowTimes',datetime(2020,5,5,12:36,0,0));
>> head(tt)
ans =
  8×1 timetable
            Time             Var1  
    ____________________    _______
    05-May-2020 12:00:00    0.63274
    05-May-2020 13:00:00    0.43933
    05-May-2020 14:00:00     0.8247
    05-May-2020 15:00:00    0.68898
    05-May-2020 16:00:00    0.70221
    05-May-2020 17:00:00    0.98715
    05-May-2020 18:00:00    0.95441
    05-May-2020 19:00:00    0.85127
>> retime(tt,'regular','mean','TimeStep',caldays(1))
ans =
  2×1 timetable
       Time         Var1  
    ___________    _______
    05-May-2020    0.62712
    06-May-2020    0.63855

[dpb]

Hmmmm, Peter. I can't find what I had tried in command history now to see what I did wrong to draw the conclusion couldn't get there from here...somehow I had convinced myself something wasn't right but can't reproduce what that was at the moment.

Thanks for straightening out...

[Peter Perkins]

A rare misstep indeed!

Answer 2

[Steven Lord]

Pass a datetime vector as the newTimes input to retime as shown in the Interpolate Timetable Data to Time Vector example on the documentation page.