daily max -min , sum, average of hourly data sets.?

hi,

I have created one mat file (attached). the first column is dates the second column is temperature- here I want to find daily max and min the third column is rainfall- here daily sum I don't need 4th and 5th column but for this time make an average.

in the date column, time is not given but it is an hourly data.(same date 24 times.)

i hope you understand

Answer 1

[Andrei Bobrov]

[y,m,d] = datevec(tempdata(:,1));
[a,~,c] = unique([y,m,d],'rows');
out = [a, zeros(size(a,1),7)];
out(:,4) = accumarray(c,tempdata(:,2),[],@nanmin);
out(:,5) = accumarray(c,tempdata(:,2),[],@nanmax);
out(:,6) = accumarray(c,tempdata(:,3),[],@nansum);
[ii,jj] = ndgrid(c,1:4);
out(:,7:10) = accumarray([ii(:),jj(:)],reshape(tempdata(:,4:7),[],1),[],@nanmean);

[pruth]

thank you sir.

[pruth]

sir, what shall I do if want repeats this process after every 3 column?

min max for the first column, the sum of the second column, mean for the third column,

and again action repeats . min max for the fourth column and so on...

Answer 2

[Steven Lord]

If you're using release R2016b or later, I recommend storing your data in a timetable and using the retime function to aggregate data over daily time bins as shown in the second example, "Aggregate Timetable Data and Calculate Mean Values", on that documentation page.

[pruth]

hello steven , thanks for the reply,

I use R2013a.