irlba                   Find a few approximate singular values and
                        corresponding singular vectors of a matrix.
partial_eigen           Find a few approximate largest eigenvalues and
                        corresponding eigenvectors of a symmetric
                        matrix.
prcomp_irlba            Principal Components Analysis
ssvd                    Sparse regularized low-rank matrix
                        approximation.
summary.irlba_prcomp    Summary method for truncated pca objects
                        computed by 'prcomp_irlba'.
svdr                    Find a few approximate largest singular values
                        and corresponding singular vectors of a matrix.
