Hourly, Daily, Weekly, averages with accumarray and unique

I have a data set that is set up like this: Column one is a timestamp, column 2 is a start time, column 3 is the end time, and columns 4 to 20 are data. This is a table with 8544 rows and 20 columns.

Time Stamp   Start time        End Time           Data 4:26
89899898     "01/01/16 01:00"  "01/01/16 01:59"   .09 ... etc

Since this data is in a table, I first converted to an array, and then used unique to specify unique times and accumarray to give me the averages. Problem is, I don't get a value out with "out_hour", I get an error. My "ah" gives me a matrix that is 8544 by 2 columns, with all the start and end times. My "ch" gives me a 8544 row by 1 column matrix. I have a similar set up for the daily and weekly averages. For some reason, "out_hour" doesn't provide me with a value, just an error. Any thoughts?

Data1 = table2array(Data);
%average values per hour
[ah,~,ch] = unique(Data1(:,2:3),'rows');
out_hour = [ah,accumarray(ch,Data1(:,4:26),[],@nanmean)];

Answer 1

[Sean de Wolski]

Use the newer and easier retime function. Turn your table into a timetable (table2timetable) and then just call retime with the hourly or monthly option.

[Armando Domingos]

Thanks, this worked really well.