V must be a 3-D array. The lengths of X,Y and Z must match the size of V. X,Y and Z must all be vectors or all be arrays. Matrices X,Y and Z must be the same size as V. X,Y and Z must be vectors when V is. X,Y and Z must be the same length as V. XI,YI, and ZI must be the same size or vectors of different orientations.