run a series of epochs of the umap optimization
optimize_embedding(embedding, pairs, eps, epns, abg, alpha0, num_epochs)
matrix with embedding coordinates (This should be transpose of final embedding, with coordinates along columns, items in rows)
matrix with two columns; rows should linke to (from, to); indexes 0-based
numeric vector, epochs for next sample
numeric vector, epochs for next negative sample
vector with configuration parameters, a, b, gamma, move_other
numeric, initial learning rate