Determine whether input is vector
If the input array A has more than two dimensions, then
isvector(A) always returns logical 0
(false). For example, an array of size 1-by-1-by-N is not a
vector.
isvector(A) function does not have any special behavior for
dimension lengths equal to 0. For example, isvector(A) returns logical
1 (true) if the size of A is 0-by-1. But,
isvector(A) returns logical 0
(false) if the size of A is 0-by-3.