Fig. 2From: Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysisClustering 500 extracted components from 50 runs of NMF with 10 components in each run: a inner similarity of each cluster for HALS; b inner similarity of each cluster for NMF_MU; c stability index (\(I_{q}\)) and the number of components in each cluster for HALS; d stability index (\(I_{q}\)) and the number of components in each cluster for NMF_MUBack to article page