Fig. 4: Schematic illustration of matrix- and tensor-based recommender systems.
From: Recommender system for discovery of inorganic compounds
a A simplified scheme of the matrix-based recommender system used in E-commerce. b An example of a 3rd order tensor expressing binary compounds. c Using the Tucker decomposition method, a large tensor can be approximated by a product of a small core tensor and three matrices. Adopted from ref. 14 with small modifications.
