In MoMA three deflation schemes are provided for PCA.
Using terminology in the reference, they are Hotelling's deflation,
two-way projection deflation, and Schur complement deflation.
See the parameter deflation_scheme argument in the function
moma_sfpca. Also refer to the reference below
for theoretical properties.
Michael Weylandt. "Multi-Rank Sparse and Functional PCA: Manifold Optimization and Iterative Deflation Techniques." arXiv:1907.12012v1, 2019.