Hi, this article is really interesting. I have not read it fully, but sparse NMF formulations is something really to look at in the future. However they use it for HPSS, for which we already have an algorithm, with 3 modes and lots of paramrters. I think between this and pre-trained NMF you should be able to do interestign things. For example you could pre-train NMF with the components resulting from HPSS, then re-train with the mixed signal…