Generalized PCA with row metric M and column metric A (genpca()), following Allen, Grosenick & Taylor (2014).
Covariance-based GPCA from a precomputed C = X' M X (genpca_cov()), with eigen and gmd paths.
Multiple computational backends: eigen, spectra (matrix-free C++ via RSpectra), randomized, and deflation. The auto heuristic picks among them.
Generalized PLS / PLS-SVD on two blocks (genpls(), genplsc()) and an operator-level interface (gplssvd_op()) that avoids materialising whitened matrices.
Sparse functional PCA (sfpca()), regularised PLS (rpls()), and matrix-normal PCA via maximum residual likelihood (mnpca_mrl()).