supermat function

Matrix unfolding

Produces matricizations of a three-way array into matrices denoted as super-matrices.

supermat(X)

Arguments

• X: Array to be unfolded

Returns

A list including the following components: - Xa: Super-matrix with B-mode entities nested within C-mode entities (all the frontal slices of the array next to each other)

• Xb: Super-matrix with C-mode entities nested within A-mode entities (all the horizontal slices of the array next to each other)

• Xc: Super-matrix with A-mode entities nested within B-mode entities (all the lateral slices of the array next to each other)

References

H.A.L. Kiers (2000). Towards a standardized notation and terminology in multiway analysis. Journal of Chemometrics 14:105--122.

Author(s)

Maria Antonietta Del Ferraro mariaantonietta.delferraro@yahoo.it

Henk A.L. Kiers h.a.l.kiers@rug.nl

Paolo Giordani paolo.giordani@uniroma1.it

Examples

# array (2x2x2) with integers from 1 to 8
X <- array(1:8,c(2,2,2))
Y <- supermat(X)
# matricized arrays
Y$Xa
Y$Xb
Y$Xc