Comments on: A unified algorithm for principal and minor components extraction.
This letter points out that the unified algorithm given by Chen et al. (Chen, T., Amari, S., & Lin, Q. (1998). Neural Networks, 11, 385-390) is a direct generalization of our invariant-norm algorithm. However, this direct-generalized unified algorithm is not practical from the learning point of view as the involved computations are intensive. As a matter of fact, a more effective generalization is made available.