1. A non-transitory storage medium storing instructions executable by an electronic data processing device to perform a method including minimizing a convex regularized loss function respective to a prediction tensor X of order K having dimensions n 1 , n 2 ,. .. , n K to generate an optimized prediction tensor of order K where K>2 and the convex regularized loss function comprises a linear combination of (i) a loss function e(X; Y) comparing the prediction tensor X and an observation tensor Y of order K representing a set of observations and (ii) a regularization parameter λ∥X∥ * where λ is a scalar value and ∥X∥ * is a K-th order matrix norm decomposition of the tensor trace norm of the prediction tensor X given by  X  * = 1 K ⁢ ( min A 1 ⊗ A 2 ⊗ … ⊗ A K = X ⁢ (  A 1  K K +  A 2  K K + … +  A K  K K ) ) where A k ε n k ×R , R=max{n 1 , n 2 ,. .. , n K }, ∥A k ∥ K is the K-th order matrix norm of A k , and denotes the outer matrix product operator.