Comparison of Initialization Techniques for the Accurate Extraction of Muscle Synergies from Myoelectric Signals via Nonnegative Matrix Factorization

Figure 3

Performance of NNMF with three different initialization techniques. Average cosine similarity between the synergies extracted from an initialization technique and the original simulated synergies . For each of the 20 correlation levels between the activation coefficients , the performance is reported as median ± median absolute deviation across 100 realizations. (a) Data generated with independent synergy vectors . (b) Data generated with dependent synergy vectors .