** updates ### 11 Dec, 2019 - fix a convergence rate issue - reconstruct a safer way to perform multi-threads computing in R environment without affecting other packages - perform an initialize procedure to determine proper step sizes for optimization for a better performance - update the status of cited papers

18 Mar, 2019

30 Dec, 2018

11 Oct, 2018

10 Oct, 2018

Resubmission

Fix cran comments

30 Sep, 2018

fix the bug when input K = 1