Mode-m flattening
From HandWiki
In multilinear algebra, mode-m flattening[1] (also matrixizing, matricizing, or unfolding) is an operation that reshapes a tensor (a multi-way array) [math]\displaystyle{ \mathcal{A} }[/math] into a matrix denoted by [math]\displaystyle{ A_{[m]} }[/math] (a two-way array). Matrixizing may be regarded as a generalization of the mathematical concept of vectorization.
Applications
This operation is used widely in Parafac and HOSVD.
References
- ↑ Eldén, L.; Savas, B. (2009-01-01). "A Newton–Grassmann Method for Computing the Best Multilinear Rank-$(r_1,$ $r_2,$ $r_3)$ Approximation of a Tensor". SIAM Journal on Matrix Analysis and Applications 31 (2): 248–271. doi:10.1137/070688316. ISSN 0895-4798. http://epubs.siam.org/doi/10.1137/070688316.