Fig. 1

Workflow of the framework. The distribution of each chromatin modification is expressed as a weighted sum of all other modifications. The resulting coefficients are recorded in an affinity matrix. The affinity matrix is enforced to be sparse. Consequently, the chromatin modifications are clustered into different groups via hierarchical clustering. Then, a representative is selected for each cluster. After the subset is identified, the regulatory functions associated with these combinatorial patterns are further analyzed. The identified patterns then further lead to discovery of novel regulatory regions