The maxk and mink functions (introduced in R2017b) would make this a bit more efficient. Lacking them, use sort.
Try this —
A = randn(1007, 94);
for k = 1:size(A,2)
[pks, locs] = findpeaks(A(:,k));
[~,ix] = sort(pks);
minpk{:,k} = [pks(ix(1:2)) locs(ix(1:2))];
maxpk{:,k} = [pks(ix(end-1:end)) locs(ix(end-1:end))];
end
maxpk{1} % View Result
minpk{1} % View Result
.
