run one epoch of the umap optimization
optimize_epoch(embedding, pairs, adjust, nns, abg, alpha)
matrix with embedding coordinates (coordinates along columns)
matrix with rows: from to; indexes must be 0-based
vector with 0/1 whether to adjust or not
vector with negative-neighbors-set size
vector with configuration parameters, a, b, gamma, move_other
numeric learning rate for this epoch
matrix with columns: eps, epns, eon2s, eons, nns (in that order)