Table 1: Special cases of Principal Component Analysis.

Principal Component Regression
(PCR)
Soft Independent Modelling of Class Analogy
(SIMCA)
Multi-way Principal Component Analysis
(MPCA)

It is a regression version of PCA because it uses the scores of the PCA model to correlate.It is a clustering method that constructs separate PCA models for a prior determined class of data that operates on the residual matirxIt operates with higher dimensional data-array by unfolding it prior to bi-linear PCA