1. ones(X) ones(N, M)
% return a matrix or N-dimensional array whose elements are all 1.
2. zeros(X) zeros(N, M)
% return a matrix or N-dimensional array whose elements are all 0.
3. rand(X) rand(N, M)
% return a matrix with random elements uniformly distributed on the interval (0,1).
4. hist(Y, X, NORM)
% produce histogram counts or plots.
5. eye(X) eye(N, M)
% return an identity matrix.
6. pwd
% return the current working directory.
7. cd dir
% change the current working directory to DIR.
8. who
% list variables
9. A(:)
% put all elements of A into a single vector.
10. A * B
% multiple
11. A .* B
% multiple each element
12. A‘
% matrix transpose
13. find
% example find specific rows
% idx = find(X(:, 2) == 8)
% Y = X(idx, :)