Parallel Analysis via time-wise permutation
choose_rank_pa.RdComputes a null distribution for the leading singular value by permuting time
indices independently within each column and selecting k where observed
singular values exceed the (1 - alpha) quantile of the null.
See also
choose_rank_gd() for Gavish-Donoho approach,
blocked_cv_recon_error() for cross-validation approach
Other rank selection:
blocked_cv_recon_error(),
choose_rank_gd()