Dear all, The following paper is a survey on sparse representation. We focus on applying sparse representation to feature selection. J. Gui, Z. Sun, S. Ji, D. Tao, and T. Tan, "Feature Selection Based on Structured Sparsity: A Comprehensive Study", IEEE Transactions on Neural Networks and Learning Systems, vol. 28, no. 7, pp. 1490-1507, 2017. The paper and matlab code can be downloaded from http://www.escience.cn/people/guijie/Publication.html. If you have any problem, feel free to contact me. Best regards! -- ＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊ Associate Professor Jie (Joe) Gui, Ph.D., SMIEEE Institute of Intelligent Machines, Chinese Academy of Sciences (CAS) Hefei 230031, Anhui, China Homepage: http://www.escience.cn/people/guijie/index.html ＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊