Find negative in every n rows

I have a 2184 x 14 matrix. In column 1 is the datenum value and in column 14 the values that I want to consider. The other columns contain some other data.

I want to consider the first 24rows if any of the values in column 14 are negative. I want to delete the first 24rows and then repeat this for the following 24rows.

Answer 1

[Andrei Bobrov]

One way

% A - your data [2184 x 14]
ii = ceil((1:size(A,1))'/24);
jj = accumarray(ii,A(:,14),[],@(x)all(x >= 0)); % EDIT
out = A(jj(ii),:);

[David du Preez]

That does not work. It does not find any negative neither removes them. attached in the matrix in question

[Andrei Bobrov]

I'm fixed my answer.

Answer 2

[Jan]

Data   = rand(2184, 14) - 0.1;  % Test data
D      = reshape(Data, 24, [], 14);
Match  = any(D(:, :, 14) < 0, 1);
Result = reshape(D(:, Match, :)), [], 14);