MATLAB: How to filter a date column so it just considers every 5 minutes observations for each day

Question

Hi everyone!

I have the next column where each number represents the date ('yyyymmddHHMM' in this order):

As you can see from the image here I have one year (1990), one month (january), two days (02 and 03) and different hours with one minute distance.

What I wanted to do is to filter this column for every 5 minutes. First starting every day in the first minute (10:00 vs 10:05) and continuing with the second minute (10:01 vs 10:06) and so on.

I have used the next comand to filter my data:

C5= cell(length(C)-2,1);

for ii=1:length(C5)

   C5{ii} = C(ii:5:end)';

end

Obtaining the next results:

But as you can see my command is not restarting the 5 minutes jump when is another day and therefore the columns are "outdated" for my purposes.

For example, the first column form the last image should look this:

How can I modify my code so it restarts the 5 minutes jumps when is another day?

Thanks a lot for your help!

AngelaT

Answer 1

You can use the mod operator. Lets say the data vector is x and it needs to rearranged in C. Try the following:

C = cell(1,5); % Pre-allocate the cell array
for i = 1:5
    C{1,i} = x(mod(x,5) == i-1);
end

Hope this helps!