In mathematics, matricization (also matricisation, matricizing, unfolding, or flattening) is the operation that turns a tensor (a multi-dimensional array) into a matrix (a two-dimensional array).
Matricization may be regarded as a generalization of the mathematical concept of vectorization.
Matricization may be applied in connection with determination of the factors in the PARAFAC model.
References
Matricization Wikipedia(Text) CC BY-SA