filter function for aggregation of data

Hi everybody! I'm wondering if there is a way to solve the following problem in a more efficient way instead of a for cycle: I have a vector of hourly values and I would like to aggregate these values to 3 hour values with a moving window such that the first value would be the sum of the first three elements, the second value the sum of element 2,3 and 4, the third value the sum of element 3,4 and 5 and so on... I used a for loop but this takes me a lot of time. I knwo that this can be done with the filter function but I didn't understand how it works exactly. Does anybody know how to solve it? Thanks a lot Camilla

Answer 1

[Thorsten]

 x = randi(10, [1 10]); % sample data
 F = 1/3*ones(1,3); % filter
 xm3 = conv(x, F, 'valid');

[Camilla Santicoli]

Thank you Thorsen but like this is makes the average, not the sum

[Thorsten]

True. To get the sum, just use the filter

F = ones(1,3);

[Camilla Santicoli]

thank you very much!

[Thorsten]

Please accept the answer.