KMHFA                   Estimating the Pair of Factor Numbers via
                        Eigenvalue Ratios or Rank Minimization.
KPCA                    Estimating the Pair of Factor Numbers via
                        Eigenvalue Ratios Corresponding to alpha-PCA
KPE                     Estimating the Pair of Factor Numbers via
                        Eigenvalue Ratios Corresponding to PE
MHFA                    Matrix Huber Factor Analysis
PE                      Projected Estimation for Large-Dimensional
                        Matrix Factor Models
alpha_PCA               Statistical Inference for High-Dimensional
                        Matrix-Variate Factor Model
