Delete rows based on column value

Hi. I have a 8761x14 matrix. I wanted to consider the first 24 rows as I have hourly data. If all the values in column 8 are zero (ie. 24 zeros) I want to delete all 24 rows and then repeat this considering every 24 rows.

Answer 1

[Andrei Bobrov]

Let A - your matrix [8761 x 14]

[m,n] = size(A);
A1 = [A; nan(mod(-m,24),n)];
A1 = reshape(A1',n,24,[]);
Aout = A1(:,:,any(A1(8,:,:) ~= 0,2));
Aout = reshape(Aout,n,[])';

or

m = size(A,1);
i0 = ceil((1:m)'/24);
Aout = A(repelem(accumarray(i0,A(:,8)) ~= 0,accumarray(i0,1)),:);