About the Authors

Jinfeng Zhang

Affiliation Department of Statistics, Harvard University, Cambridge, Massachusetts, United States of America

Jun S Liu

To whom correspondence should be addressed. E-mail: jliu@stat.harvard.edu

Affiliation Department of Statistics, Harvard University, Cambridge, Massachusetts, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

JZ and JSL conceived and designed the experiments and wrote the paper. JZ performed the experiments, analyzed the data, and contributed reagents/materials/analysis tools.