duration.ismatrix
duration: TF = ismatrix (D)
Return true if duration array is a 2-D array.
TF = ismatrix (D) returns a logical scalar TF,
which is true if the duration array D is a matrix and
false otherwise. A matrix is an array of any type where
ndims (D) == 2. By definition, a scalar is also a matrix.
Source Code: duration