根据输入内容，输出对应标题
This paper formulates an index-selecting model  for complex system based on gray clustering and  rough set theory, which can produce several indexes  to reflect the situation of the complex system, accordingly service and finally simplify the complex  system. At the end of this paper, an empirical  analysis of the real estate system of Wuhan brings a  conclusion that the model involved is scientific and  effective.
An Index Selecting Model for Complex System Based on Grey System and Rough Set Theory and Its Application