1 Ministry of Education Key Laboratory of Bioinformatics, Bioinformatics Division at the Beijing National Research Center for Information Science and Technology, Center for Synthetic and Systems Biology, Department of Automation, Tsinghua University, Beijing 100084, China.
2 School of Mathematical Sciences and LPMC, Nankai University, Tianjin 300071, China. Electronic address: chenshengquan@nankai.edu.cn.
3 Ministry of Education Key Laboratory of Bioinformatics, Bioinformatics Division at the Beijing National Research Center for Information Science and Technology, Center for Synthetic and Systems Biology, Department of Automation, Tsinghua University, Beijing 100084, China. Electronic address: ruijiang@tsinghua.edu.cn.