Results from synthetic dataset A (a) Original dataset with the two embedded patterns. (b) Dataset sorted by two-way hierarchical clustering. Dataset sorted by (c) the first basis gene and basis experiment and (d) the second basis gene and basis experiment yielded by ns NMF at k = 3. Conditions belonging to pattern Pla are marked in green and conditions belonging to pattern P2a are depicted in orange. The two plots over the heatmaps represent the coefficients of conditions in each sorted basis gene.