duration.iscolumn
duration: TF = iscolumn (D)
Return true if duration array is a column vector.
TF = iscolumn (D) returns a logical scalar TF,
which is true if the duration array D is a column vector
and false otherwise. A column vector is a 2-D array for which
size (D) returns [N, 1] with non-negative
N. By definition, a scalar is also a column vector.
Source Code: duration